Stocking ideas for 65, 55, 20's, and 10

[Sawyer]

I have many tanks with no fish and eventually I want to stock them but I'm not sure if my plans are over or under stocking. so just let me know if it's over or under stocked, if the fish aren't compatible, if certain fish would be better in other tanks, recommend numbers, etc :)

65gal- After I set up this tank I'll have 6 common/comet goldfish (3-4 inches long), 1 Ryukin goldfish (2 in.), and 2 plecos (3-6 in.) (these are fish I already have) but the plecos will move into a bigger tank when they get older and the commons/comets will move into my pond. When will they outgrow the tank?
When they do I'll have:
6 fancy goldfish (2 veiltails, 2 ryukins, oranda, black moors), 3-5 clown loaches, and 3 small plecos (5 inches or under). I know the clowns and plecos are tropical and goldfish aren't but the tank will stay around 70-75 year round without any heater since I live in a warm area. Do plecos and loaches need warmer than that?

55gal- 1 angelfish, 8 corydoras, 6 marbled hatchetfish, 18 tetras (ones that get around 2 inches). Is this okay? Will the angel eat/harass the tetras, hatchetfish?

40gal- 1 convict cichlid, 6 tiger barbs, 2 cherry barbs, 1 German blue/gold ram, 1 krib

20 gal- sorority of at least 10 female bettas

20gal- 3 kuhli loaches, mollies, swordtails

10 gal- Dwarf crayfish (dunno how many I should have), a trio of honey gouramis (2 females, 1 male), some sparkling gouarmis (again, don't know how many)

10 gal- Guppies and dwarf rasboras

10gal-at least 6 small tetras, about 3 platys, 3 otos

10gal-6 zebra danios and 6 glofish.

which tank would glass catfish be best in? Someone gave me two on the 19th along with a pleco and either a neon or cardinal (can't tell the difference) and I know that they need at last 6 in a group and grow to 6 inches. Could I put them in the 55g and have less tetras to make up for adding them?

Note: all my tanks will have good filtration (my 65 has a great wet/dry filtration that will be perfect for messy fish like golds and plecos) and they'll all have tons of live plants and plenty of hiding spots for fish. Also, I know guppies, platys, mollies, etc breed a lot but the other fish will probably eat them and I was planning on having an outdoor kiddie pool "pond" for "extra" fish (the kiddie pool would be in a shady area, buried in the ground, the top have a screen, plants that require low lighting like java fern, and I'd have to find someplace to house them indoors in winter)

[majortank]

Sounds like a lot of goldfish for a 65, no? I don't know mcuh about them but I would think that would be way overstocked. 12 goldfish? Also, water temps for Goldfish and loaches are different. That tank would not work IMO.

3 honey gouramis and "some sparkling gouramis" in a 10g is definitely overstocked. One honey in a 10g and a small school is ok.

Some swordtails get pretty long, 20gal may be too small.

[GusBus27]

I don't know if I would trust the convict with the ram...

I've kept plecos in 72-76 degree water without problems...

Can't really help on the community tanks... good luck

[Sawyer]

Not 12 goldfish, the 6 commons/comets and ryukin goldfish while they're small, when they outgrow that tank the commons/comets will go in my pond and I'll leave the Ryukin in there and get 5 other fancy goldfish. The plecos will move out when they get too large as well. If I do get Clown loaches, same goes for them, they get upgraded when they get too large for the tank (and they're slow growers, so I read they should be fine in a 65g for about 4 years).

Really? I read a trio of honey gouramis is recommended for a 10g.

Yeah, I thought that might be a problem. they grow to about 4 inches, right?

I don't know if I would trust the convict with the ram...


True, maybe I'll skip the ram or not have it in the 55g. rams are like 2inches and much more peaceful than the others I listed for that tank, so a ram probably wouldn't do well with them.

[Blitzkrieger]

Not 12 goldfish, the 6 commons/comets and ryukin goldfish while they're small, when they outgrow that tank the commons/comets will go in my pond

What kind of a pond are you talking about? Depending on your pond type, it is illegal to dump them.

Realistically, you should get fish for your aquariums that you plan on keeping in your aquarium. It is similar to buying a pony to live with you in the city, sure a pony may be cute to start off with and fit just fine in your back yard, but are you going to go out to the local state park and release him when it gets to big?

[Sawyer]

What kind of a pond are you talking about? Depending on your pond type, it is illegal to dump them.

Realistically, you should get fish for your aquariums that you plan on keeping in your aquarium. It is similar to buying a pony to live with you in the city, sure a pony may be cute to start off with and fit just fine in your back yard, but are you going to go out to the local state park and release him when it gets to big?

No, of course not. I'd never dump my pets. The pond is in my backyard (it's mine) and doesn't go into any sort of waterway. My parents might not let me put them in there though because they're afraid a heron might come and eat them or something, which is possible... So if I can't do that I'll make a pond that will fit all 6 of the commons/comets and put a screening/aviary netting type thing over it. I already have the 6 commons/comets and the ryukin too, they aren't fish I'm planning to get.

[Sawyer]

This is my new revised list. I think it would work better.

10g- 4 sparkling gouarmis (3 females, 1 male), 3 otos
10g-6 neon/cardinals, 6 glass catfish
10g-2 German blue/gold rams, 6 tetras, 1 honey gouarmi,
10g-Guppies, spotted rasboras, white cloud minnows
20g- 6 cherry barbs, 1 pearl gourami, 3 kuhli loaches
20g-sorority of at least 10 female bettas
40g- platys, swordtails, 1 krib, 6 zebra danios, 6 glofish, 6 cories
55g-1 angel, 12 tiger barbs, 1 rainbow shark, 1 red tailed shark
65g-Now: 6 comets/commons, 1 ryukin, 2 plecos. Those are fish I have now. The commons/comets and the plecos will eventually outgrow the tank of course (right now the golds are 2-4 inches and the plecos 3-6 inches) the golds will go out to my pond and the plecos upgraded to larger tank when they get too big) so after they do I was thinking 6 fancy goldfish (1 black moor, 1 oranda, 2 ryukins, 1 veiltail, 1 pearlscale) and I wanted 3-5 clown loaches. I know the clowns will outgrow the tank (though that'll take like 4 years I read) but I can upgrade them and I know that clowns are tropical and goldfish are coldwater but my unheated tanks will stay 70-77 F year round (Right now they're 76 F).

I will probably add shrimp and/or snails to any of the ones where the fish won't eat the shrimp/snails, like the 10's & 40. I'm not sure about the others. I have no idea how the fish I planned for the 55 would react to shrimp/snails and I know loaches and bettas like to eat shrimp.

I don't suppose mollies and 1 convict cichlid would go in any of these tanks? I like them, but they don't seem to work with any of these. I read that mollies are fin nippers and convicts are kind of aggressive.

[bluekrissyspike]

clown loaches like to chase and gently nip each others tails. in my experience they will stress the goldies out and probably tear their tail fins

[Kashta]

Hi Sawyer! Welcome to the hobby. I'm glad you've joined us and hope you enjoy the site as much as the rest of us do.

You're asking such great questions in this thread. Glad to see another newcomer who's willing to take the time and effort to thoroughly research and plan for the tanks and fish's care before getting them. Bravo!

You're so lucky you have a place for a nice pond setup. I'm envious! Since you're asking for specific info about goldfish care, I thought I'd direct you to our Cold/Temperate Water Forum. We have many very knowledgeable members contributing to this topic of goldfish keeping. If you'd like to post a separate thread in that section, more of our goldfish experts will see this and be able to share the expertise they have to offer. You'll find that forum here: http://www.aquariacentral.com/forums/forumdisplay.php?f=26.

In the meantime, I thought I'd pull out the goldfish questions you've asked here and give you some general info relating to them.

First, the different types of goldfish we keep are all the same species, descending from the same common carp. This is similar to dogs being of the same species with vast differences between one type (or breed) and another. Also like dogs, different goldfish "breeds" are identified by their physical characteristics; i.e., size, body type, finnage, and other specific distinctions. And each of these types have certain care requirements.
Pond fish - Comets, commons, wakins, shubunkins... are the largest goldfish with long, slender body types that grow to approx 12-18 inches in length. These are primarly bred for pond environments but can also be kept in aquariums. Requires a minimum of 20 gallons of water per fish.

Fancies - Orandas, ryukins, lionheads, ranchu... smaller goldfish with rounded, egg-shaped bodies that grow to approx. 10 inches in length. These fish need a minimum of 15 gallons per fish.

Special needs - Pearlscales, telescopes, celestials, tosakins... also considered "fancy" varieties but have been specifically bred for certain physical features (deformities) which make them much more fragile and vulnerable; i.e., delicate rounded scales, bulging or upturned eyes, and so on. These fish should only be kept with other goldfish of the same type for their own protection and should not be mixed with larger, faster, more boisterous pond fish or fancies.
Having all this out of the way, I'll get back to the 65 gallon tank setup and outdoor pond option you were asking about.


I have many tanks with no fish and eventually I want to stock them but I'm not sure if my plans are over or under stocking. so just let me know if it's over or under stocked, if the fish aren't compatible, if certain fish would be better in other tanks, recommend numbers, etc

65gal- After I set up this tank I'll have 6 common/comet goldfish (3-4 inches long), 1 Ryukin goldfish (2 in.), and 2 plecos (3-6 in.) (these are fish I already have) but the plecos will move into a bigger tank when they get older and the commons/comets will move into my pond. When will they outgrow the tank?

When they do I'll have:
6 fancy goldfish (2 veiltails, 2 ryukins, oranda, black moors), 3-5 clown loaches, and 3 small plecos (5 inches or under). I know the clowns and plecos are tropical and goldfish aren't but the tank will stay around 70-75 year round without any heater since I live in a warm area.

Note: all my tanks will have good filtration (my 65 has a great wet/dry filtration that will be perfect for messy fish like golds and plecos) and they'll all have tons of live plants and plenty of hiding spots for fish.

We need to stop already at the point where you list the 6 commons and comet goldfish that are already 3-4 inches long. These 6 fish at that size have already outgrown your 65 gallon tank and should be moved immediately to a pond setting or at least a 100-120 gallon tank if kept indoors. I realize they still seem very small now, but the volume of water they need to continue growing and developing normally in healthy condition, requires this. If they are kept in a smaller 65 gallon tank any longer, they will naturally produce a chemical which will stunt their natural rate of growth and seriously weaken their immune system -- risking a wide range of diseases that can lead to premature death, and drastically shortening their potential lifespan. If given the full 20 gallons per fish volume/space and proper care NOW, each of these fish will more than double in length, reaching approx. 8-10 inches within the next 6 months. Your 65 gallon tank can safely house only 3 of these goldfish at their present size.

The 6 fancies you intend to keep together would need 15 gallons of water per fish, thus requiring a minimum tank size of 90 gallons or more. Your 65 gallon tank would work well for only 4 fancy type goldfish.

The clown loaches and plecos are not compatible with goldfish at all. This has already been mentioned about the loaches in this thread. For more information about goldfish-pleco incompatibility, I'll add here the information I posted recently which explains why.

Plecos should never be kept in the same tank with goldfish for several specific reasons...

Aside from (#1) their natural taste for the slime coat produced by high bodied fish, like goldfish, they also (#2) need vastly different tank setups.. tropical conditions vs. coldwater/temperate conditions.

(#3) Competition for food becomes a big problem, as well, for the much less gregarious pleco living in the same tank with such active, boisterous goldfish. Goldfish are omnivores who are constantly looking for leftover bits of food -- which is the same as that needed by the pleco. This makes it a constant challenge to keep a pleco well fed in the same tank.

Most importantly, goldfish are still a pond fish species despite the fact that we keep them in aquariums. They are much more prone to problems of parasitic infestation/illness because of this.... goldfish are also more susceptible to illnesses/disease resulting from their unique digestive limitations. Invariably, when the need for medication arises for the welfare and good health of the goldfish, (#4) plecos cannot tolerate the same medications and dosages needed for treatment.

Needing to keep the water clean and water parameters stable in goldfish tanks is also a major consideration, as (#5) both goldfish and plecos produce an inordinately high level of waste. Adding a pleco to an already heavy bioload makes it that much more difficult to maintain the good water quality conditions necessary to prevent sickness, disease, parasites, and other common health problems for the goldfish.

If you'd like to browse through the entire thread for the discussion we had about this a week or so ago, you'll find that in our coldwater section by following the link below.
Subject: "Death Trap"
Link to full thread: http://www.aquariacentral.com/forums/showthread.php?t=191001
The recommendations I have to give you about these goldfish may seem disappointing. But if you're willing to spend some time browsing through the last one/two dozen threads posted by our members in the coldwater forum, you will quickly understand why this is so important. We have many threads there describing an assortment of very serious, life-threatening health problems which resulted from keeping goldfish in tanks that are too small for too long a period of time.

Please look into this further as you consider realistic options for the fish you want to keep. Our experienced members who keep goldfish have already learned to avoid making the same very common mistakes - the hard way. And our beginning goldfish keepers are going through a lot of anguish trying to treat and care for sick and dying fish they have, simply because no one was there to give them the proper advice and warn them about these problems ahead of time.

[Sawyer]

Thanks for all the info, I didn't realize keeping them all in the 65g for now could be dangerous to their health and cause them to not grow properly. For the 6 commons/comets, how many gallons do they need when full grown? I'm considering making a pond for them to stay in their whole life, instead of putting them in my "big pond". That way, if I made them their own pond, I could put netting over it to make sure nothing ever happens to them. For now, I can put them in a large kiddie pool (sink the kiddie pool into the ground in a shady area and put netting over it). I'm sure I could find at least 100 gallon kiddie pool..

I hope the goldfish aren't already stunted or unhealthy. I adopted them from someone keeping them in a 5g and 2.5g with a bunch of other fish and I have no idea how long they were in those small tanks.

Are clown loaches and plecos compatible?

[Lupin]

This is my new revised list. I think it would work better.

10g- 4 sparkling gouarmis (3 females, 1 male), 3 otos
10g-6 neon/cardinals, 6 glass catfish
10g-2 German blue/gold rams, 6 tetras, 1 honey gouarmi,
10g-Guppies, spotted rasboras, white cloud minnows
20g- 6 cherry barbs, 1 pearl gourami, 3 kuhli loaches
20g-sorority of at least 10 female bettas
40g- platys, swordtails, 1 krib, 6 zebra danios, 6 glofish, 6 cories
55g-1 angel, 12 tiger barbs, 1 rainbow shark, 1 red tailed shark
I'm leaving the 65g to be sored by Kashta.

As for these ones in red fonts, let's start with the 10g tanks. The first one is okay however I might warn you there is no easy way of determining the sexes of sparkling gouramis, no matter how you attempt to distinguish the differences in any way. Sex ratio is not an issue. As much as possible, buy the smallest and youngest of the stocks. Sparkling gouramis are not exactly long-lived species with most records of them living for barely eight months so you may need to reconsider this unless you want to go ahead. Further details can be found here (http://www.aquariacentral.com/forums/showthread.php?t=141556).

Secondly, the 10g tank in red font consisting glass catfish is ridiculously cramped. The tetras will work but glass catfish are absolutely nonos. They grow to 5-6 inches in length and as they require to be kept in groups, a 10g is quite a soft option. Get a 30g minimum for a small group of glass catfish.

The third tank will work however I suggest you keep only one ram. Why? A pair may work but in cases involving parental disputes, one of the rams will absolutely have no chance of escaping any harassments. A 20g long should be reconsidered for a pair.

Fourthly, again a 10g is not exactly spacious. What is the scientific name of the spotted rasboras? Choose only one of the three species you listed above.

The fifth tank should work. Add 5 more kuhli loaches there.

The 6th tank needs to be heavily planted in order for the sorority to work. Bettas establish pecking/ranking orders so it may be unlikely for some to survive if the alpha female happens to be overdominant.

The 7th tank will work. Lastly, the eighth tank needs to be corrected. Either ditch the angelfish, or ditch the rest. You cannot mix both the tiger barbs and sharks with angelfish for aggression issues. If you opt to stick with angelfish, go with deep bodied tetras, plecos, kuhli loaches, rams, apistogrammas, hatchetfish and rasboras as their tankmates.

If you wish to keep tiger barbs and sharks, then I suggest for loaches (which you wanted earlier), you choose Botia striata, Botia kubotai, Botia dario, Botia rostrata, Botia almorhae or Botia histrionica. Clown loaches may be an option as well if you're indeed willing to upgrade in the next few years. Skunk loaches are also an option. Despite their nasty attitude for a small sized punk, the tiger barbs and sharks can defend themselves well enough from these skunk loaches. Skunk loaches are not however suitable for community tanks in general, just the more feisty and aggressive ones.;)

I will probably add shrimp and/or snails to any of the ones where the fish won't eat the shrimp/snails, like the 10's & 40. I'm not sure about the others. I have no idea how the fish I planned for the 55 would react to shrimp/snails and I know loaches and bettas like to eat shrimp.
I must commend you for researching the compatibility and requirements thoroughly. Here are the following that will be compatible with snails and shrimps.

10g- 4 sparkling gouramis (3 females, 1 male), 3 otos
10g-6 neon/cardinals
10g-Guppies, spotted rasboras, white cloud minnows
20g- 6 cherry barbs, 1 pearl gourami, 3 kuhli loaches

If you consider keeping apple snails, please choose the mystery snails (Pomacea diffusa/bridgesii). These are absolutely plant safe and will work for plenty of planted tanks as they prefer to consume decaying and dead plant parts rather than healthy ones. Other alternatives include nerite snails, trumpet snails (Thiara, Melanoides, Brotia) and ramshorn snails (Planorbis sp.).

Assassin snails also fit the bill above but do not mix them with any other snail species intended as pets. Assassins are predatory species that prey mainly on other snails. If you wish to keep assassin snails, try breeding extra trumpet snails, ramshorns and bladder snails (Physas sp.) for their food. They will also accept bloodworms and fish foods in the absence of snail food supply with the latter only to an extent. Assassins happen to grow quickly once they reach the mark of half an inch compared to newborn ones. More information can be found here (http://arizonainverts.com/forums/index.php?showtopic=204&pid=10491&start=0&#entry10491).

As far as nerites are concerned, please make sure your tanks are loaded with algae and biofilm by allowing the tanks to become well established. They will not accept other supplemental foods except algae and possibly pea-flavored snail jello.

What you should avoid are Pomacea canaliculata, Pomacea insularum (grouped under canaliculata complex category), Pomacea haustrum and Marisa cornuarietis. All of the aforementioned species are voracious plant eaters. The canaliculata complex are the most aggressive snails by far with predatory instincts (although this is not always the norm if well-fed).

Before you start with snails, please post here your pH and KH. We need to verify here whether you need calcium dosing or not. Acidic water albeit pH no higher than 7.0 will cause the shells to erode quickly thus damaging the snails and their health. All snails require a pH no lower than 7.4 (which is not an issue to any of your fish fortunately) along with KH no lower than 3. Click here (http://www.geocities.com/popop81689/calcium) for more calcium supplement infomation and be informed I will release an article for different types of calcium sooner or later.

I don't suppose mollies and 1 convict cichlid would go in any of these tanks? I like them, but they don't seem to work with any of these. I read that mollies are fin nippers and convicts are kind of aggressive.
Mollies can go here and replace either platies or swordtails for mollies. Both the swordtails and platies can crossbreed although the point is moot anyway since most of the platies and swordtails these days are a cross of each other hence why we don't see swordtails reaching 6 inches on mark and over anymore.

40g- platys, swordtails, 1 krib, 6 zebra danios, 6 glofish, 6 cories

As far as convicts are concerned, no tanks will work with them. Consider the fact convicts are amorous at an early age and will start breeding even at an inch size despite the fact they have a potential to reach 4 inches. At this time, they become extremely aggressive to the point, they will also kill their other tankmates.

Are clown loaches and plecos compatible?
Which species of plecos are you looking for? Almost all species of plecos will work with the exception of aggressive and extremely large ones such as Acanthicus adonis. If possible, stick with L010a, Rineloricaria parva, Sturisoma panamense, bristlenose plecos, clown plecos, butterfly plecos (not to be confused with the hillstream loaches often called as Borneo plecos), king tigers, queen arabesque and most Hypancistrus sp.

[Sawyer]

Thank you!

One pleco is supposedly a Common. P. pardalis. The other I forget, I'll look it up later. It's similar looking to the Common. P. pardalis, maybe a Sailfin.The spotted rasboras are Boraras Maculatus. I'd get small plecos like Bristlenoses, clown pleco, candystripe, etc.

So.. redo

10g-4 sparkling gouramis, 3 otos
10g-guppies, shrimp, snails
10g-6 black neon tetras, 6 cories
10g-1 honey gourami, 6 neon tetras, 6 cardinals
20g-6 cherry barbs, 1 pearl gourami, 5-8 kuhli loaches
20g-sorority of at least 10 females
30g- (needed for glass catfish) 6 glass catfish, 6 zebra danios, 6 glofish
40g-1 krib, 1 or 2 blue rams, 1 angel, spotted rasboras, 6 silver hatchetfish, 6 congo tetras
55g-12 tiger barbs, 1 red tailed black shark, 3-5 clown loaches
65g-not sure. Since the golds will have a pond/pool soon, I'm not sure what I'll do with it afterwards. My plecos can probably stay in there for awhile (I dunno when they'll outgrow it) and the clowns can move in there. Maybe more plecos.. I'd love a bala shark but they get pretty big and need to be in groups... maybe a community or a cichlid tank.

Pond: for 6 commons/comets

Kiddie pools: (sunk down to keep cool/warm and with netting)

1. (at least an 80g) about 6 fancy goldfish, depending on how large it is
2. community pool: tetras, platys, swordtails, rasboras, danios, etc

[Lupin]

Good plan so far! I'd suggest giving the plecos away to someone or you may place them in the pond (not the kiddie pool) provided temperature does not fall below 18 degrees Celsius. No balas for a 65g unfortunately. You could try rainbowfish there, giant danios, arulius barbs or filament barbs.

[Sawyer]

Nah, I'm sure I can upgrade for the plecos. I couldn't put them in the pond because I wouldn't be able to find them to take them out when it gets too cold. I could make them their own pond like I'm doing for the goldfish, but it would be easier just to get a bigger tank probably.

18 Celsius is the low 60's, right?

[Kashta]

Thanks for all the info, I didn't realize keeping them all in the 65g for now could be dangerous to their health and cause them to not grow properly. For the 6 commons/comets, how many gallons do they need when full grown? I'm considering making a pond for them to stay in their whole life, instead of putting them in my "big pond". That way, if I made them their own pond, I could put netting over it to make sure nothing ever happens to them. For now, I can put them in a large kiddie pool (sink the kiddie pool into the ground in a shady area and put netting over it). I'm sure I could find at least 100 gallon kiddie pool..

I hope the goldfish aren't already stunted or unhealthy. I adopted them from someone keeping them in a 5g and 2.5g with a bunch of other fish and I have no idea how long they were in those small tanks.

Are clown loaches and plecos compatible?

Oh, I'm glad you got them out of those smaller sized tanks already! 20 gallons each is good for them for their whole lifespan.. so 100 gallons in a pond/kiddie pool is real close to the target of 120 gallons. Would only be slightly overstocked.

And yes.. a lot of people don't realize the risks and a lot of great fish are lost. This isn't what we're commonly told in the beginning. For that matter, many people believe goldfish only live a few years anyway.. never realizing they actually have a 15-40 year lifespan, if given proper conditions.

If you're not sure how old they are, then yes.. they might already be smaller than they would be otherwise at the present time. But if they're still active and healthy, they're in good shape still and will make up for their lost growth quite fast. So no worries if you can upgrade them soon, keep the water quality high, and make sure they're getting a high quality diet.

Through their first year of life, goldies develop about 65-75 percent of their full body development. During their second year, most growth occurs in their fins. Then by their third year, they're entering their peak adult form and that's when the top quality fish are sold off for shows or to breeders. So they'll recoup for a stunted beginning if we catch that early enough during their high growth developmental years.

For the most part, I believe the clown loaches and plecos are okay together. The only thing I know to question about that would be the pleco's appetite for a loaches' slime coating. Loaches don't have scales, so they would be vulnerable.. same as with goldfish, discus.. other fish like that. I have plecos, but not with loaches. So someone else will have to verify this part for you.. on their compatibility.

[Sawyer]

So all 6 will need 120 gals? Yay, I thought I'd have to make a much bigger pond than that, though I probably will make it a little bigger than necessary in case I take in anymore rescues.


For the 65g, could I have 6 dwarf neon rainbows, 1 electric yellow cichlid, 1 convict cichlid (if there's just 1 and there isn't a male and female, they can be housed with other slightly aggressive fish, right?) 4 giant danios, 4 rosy barbs, 4 filament barbs, and 4 arulius barbs? Might be overstocked.. so might have to not get 1 of the types of barbs.

[Deanthoreu]

i would put the glass cats in the 55g but then get rid of the angel fish....and the tetra's can be rather nippy..and glass cats seem to loose their tails to nippy ones. Also glass cats are not the best swimmers....they do much better with a very soft gentle water movement. so...looking at oyur list...i cant say where that might be.

rasboras, kuhli loaches, glass cats, neons .get a long very well...

[Sawyer]

are zebra danios nippy?

[Lupin]

18 Celsius is the low 60's, right?
64 degrees Fahrenheit.

For the most part, I believe the clown loaches and plecos are okay together. The only thing I know to question about that would be the pleco's appetite for a loaches' slime coating. Loaches don't have scales, so they would be vulnerable.. same as with goldfish, discus.. other fish like that. I have plecos, but not with loaches. So someone else will have to verify this part for you.. on their compatibility.
Shouldn't be an issue. Loaches are quite feisty in their own right compared to other species hence I suggested earlier some plecos will do well with loaches but there are exceptions involving size and temperament issues. By far, one of the nastiest plecos is Acanthicus adonis but these also grow to 39 inches, something not to consider at all if you want a pleco in a tank.

For the 65g, could I have 6 dwarf neon rainbows, 1 electric yellow cichlid, 1 convict cichlid (if there's just 1 and there isn't a male and female, they can be housed with other slightly aggressive fish, right?) 4 giant danios, 4 rosy barbs, 4 filament barbs, and 4 arulius barbs? Might be overstocked.. so might have to not get 1 of the types of barbs.
Please do not mix electric yellow cichlids and convicts. They will never make good community fish in general. The rest however are fine. Focus on bottom dwellers after this. You might want to note that rosy barbs prefer cooler waters so be sure your other fish will tolerate a temperature range no higher than 78 degrees Fahrenheit. Rubber lipped plecos, bristlenose plecos, L010a and clown plecos will work well here.

i would put the glass cats in the 55g but then get rid of the angel fish....and the tetra's can be rather nippy..and glass cats seem to loose their tails to nippy ones. Also glass cats are not the best swimmers....they do much better with a very soft gentle water movement. so...looking at oyur list...i cant say where that might be.
None of the tetras he listed is that nippy. Angelfish will work with glass catfish provided the tank is spacious enough to allow both species to coexist together. I rather think as Sawyer prefers only one angelfish, the compatibility issue is moot. A lone angelfish tends to mind its own business although some species may behave too dominant for the likes of others but I doubt this would happen.

are zebra danios nippy?
Unless you're keeping a large group, they can be. They're also too boisterous so bear in mind the likes of glass catfish and a few other placid tankmates will not be able to get their share of food if the zebra danios continue hogging anything. In my experience, the danios seem to eat their heart out until they fit to burst.

[Reframer]

IDK if any else mentiones it already, but I would not advise keeping that many female bettas together, even the females can get aggressive to eachother, especially if they don't have a lot of space.

[Lupin]

IDK if any else mentiones it already, but I would not advise keeping that many female bettas together, even the females can get aggressive to eachother, especially if they don't have a lot of space.
Yup, I did.
The 6th tank needs to be heavily planted in order for the sorority to work. Bettas establish pecking/ranking orders so it may be unlikely for some to survive if the alpha female happens to be overdominant.

[Sawyer]

Okay, I won't get a yellow cichlid then.

I've been reading up on betta sororities for months. At first I decided not to have one because I was scared about the fighting, but then I was reading how successful they can be as long as you do it right and it's just so tempting. You're actually supposed to overcrowd for sororities and have at the very least, 6 bettas. a 20g works best if it has at least 10. Any less than that and the aggression isn't spread out enough, in most cases. The more, the better. And the more spots for them to hide (even if it looks a bit crowded) and a heavily plant tank is best too. I'll have tanks to put them in in case of having to separate them and I'll keep an eye on them to watch for fighting.