Going in circles - how best to control phosphate?

[FishInMaryland]

Problem: brown algae, diatoms, whatever you want to call it
From reading a lot of posts, I think this is diatoms, but am not sure of exactly what to call it. It's not outrageous, and tends to coat the walls, (silk) plants, and wood and rubs off easily, but is ugly and drives me crazy.

Over the 13 months I've had the tank in my house (which I bought lock, stock, and barrel from somebody), I've battled this problem and tried lots of different things. Now, I still have phosphates in the 10ppm range, and think this is the cause of the diatoms, but don't know where the phosphate is coming from.

Can somebody tell me the optimum setup for a non-planted tank to keep phosphates to a minimum? Temperature, watts of light, amount of time to leave lights on, type of air bubbler, etc. I can put in up to 230 watts of light, but currently have less than that - don't worry about how much is there now, please just tell me what I should have. Should I keep a phosphate adsorbing media in my filter at all times? Which one?

I can get the phosphates down to about 2 ppm through water changes and use of Phos Guard, but shouldn't it go lower than that? The tap water tests negligible for phosphates and it takes no time for it to go from 2 ppm back up to the 10 ppm range. It has to be coming from something, doesn't it? Is it just the fish poop causing the problem? How often should the filters be cleaned?

I had live plants for a while, but really struggled to get them the right environment, since we're on well water, and ended up spending tons of hours housekeeping to keep the algae down, and lots of money on various chemical fertilizers, mostly to no avail. Took out all plants in April, and just have 4 silk plants in there now. The tank and gravel are MUCH cleaner, algae problem is reduced, but still have the diatoms.


Currently:
- 125 gallon acrylic tank (different from glass, since all equipment has to enter the tank from one end - so all circulation, etc., comes from one end of tank)
- 2 Fluval 404 filters, the only media in them is ceramic rings, along with 4 of the Fluval spongey things in each filter.
- 15 W UV filter, however bulb is probably old and I can't change it, or I would have a flood
- temp is about 75-77
- PH is 7.8
- 50% water changes every 4 weeks, but clean off plants and walls in between, as needed. I vacuum the gravel when I do a water change, and it is not very dirty (not like it was when I had live plants).
- Feed a smidgen (1/2 tsp) once per day, using Nutrafin (supposedly has lower phosphate) and about 12 Hikari Gold cichlid pellets. It's all gone within 2 minutes.
- 8 blood parrot cichlids, about 3-5" each
- 3 bala sharks, 3-4" each
- 1 blue channel catfish, about 4"
- Several pieces of wood for aquariums
- Couple of rocks, which I've tested to make sure they don't give off phosphates
- Tetratec Deep Water DW18 pump, hooked up to about a 15" flexible air wand

Sorry for the long post. Thanks for any suggestions.

Ruth

[RTR]

I suspect that you just need to do a lot more water changes. Can you test the nitrate levels in the tank and report on those?

[FishInMaryland]

It's hard for me to tell the difference between the shades of red at the bottom of the card...suffice it to say, nitrate is at least 40 ppm, perhaps even as high as 80. I did a 35-40 gallon water change 2 weeks ago.

I assumed when I got the tank, that I could stick to the same schedule that the previous owner did - 25% w/c every 4 weeks, clean alternate filters quarterly. And this was with an additional handful of relatively smaller fish.

What would you expect to be a "normal" w/c schedule, given the fish I have, etc.?

BTW, thanks for your response. Your wall-o-tanks and associated plumbing are quite impressive!

[Pretender]

I have on rare occasion seen 25% once a month water changes published in supposedly credible sources, but most often see anywhere from 10-25% each week recommended. I change about 13% a week, but it's only one bucket, so does not take as much time and effort as a 125 gallon tank! Most often, I've seen manufacturer instructions call for replacing filter cartridges, or cleaning filter media once a month, if not sooner. Once a quarter is awfully infrequent, it seems to me, but I don't know what Fluval recommends. I would take the spongy things out of the filter when doing your weekly water change and at least rinse them in the old water. (This might be all that "cleaning" them entails anyway.)

Nitrates can also contribute to algae, and is typically a more common problem than phosphates as too high a nitrate level is due primarily to aquarium care practices. If your nitrates are actually 40-80 ppm, you need to get them under 40 ASAP with large water changes! 40-50 is the upper limit for freshwater in the test kit instruction and other printed publications, although it seems many here like to keep it under 20. If you are having difficulty differentiating the colors, you might want to try another test kit. Although I'm sure there are several good ones, I use the Aquarium Pharmaceuticals nitrate test kit. It will easily differentiate the ranges, and I've seen it in almost every fish and pet store I go into.


Perhaps changing the UV bulb will help, too. Those are supposed to be replaced quite frequently, and if your system is not plumbed to make that replacement easy, you might want to figure out how to do so.

Hope this helps. Let us know how you do.

[FishInMaryland]

Thanks for the comments. I'll try to do 25% weekly changes, and will do a large change tomorrow. You're right - it's a nuisance in the 125 gal tank. We don't have enough water pressure (danged water saver faucets) to use the Python/waterbed thing, so it's hauling buckets for us. This requires me to get help from my husband. Had he known the maintenance required, he would never have agreed to get the tank!

Also, you're right about what "cleaning" the filters means. Along with rinsing out the spongey things in the old water, I swish around the ceramic pieces to get the crud out, then dump the old water and add fresh.

Do you have recommendations on the lights - how much and how long to leave them on?

I do have the Aq. Pharmaceuticals nitrate test kit - I think it's my eyes, not the card, that makes it hard to differentiate between 40 and 80 ppm!!

Thanks.

[RTR]

As already stated, either 40 or 80ppm is way too high. I try to operate at ~10ppm nitrate for planted tanks (some I do have to add nitrate, most I have to add phosphate).

It is kidding yourself to think that there is set percentage partial water change effective across a variety of tanks. Every setup is different, they are fed differently and the fish housed are different. Monitor nitrate production or phosphate accumulation and hit a schedule that works for you. that is the only way to find the appropriate percent partial that is good for your tank. Mine range from ~25% weekly to ~50% weekly (most of my tanks) these days, but I have operated setups requiring more than 100% weekly. I have gotten too lazy for that these days.

[Pretender]

I do have the Aq. Pharmaceuticals nitrate test kit - I think it's my eyes, not the card, that makes it hard to differentiate between 40 and 80 ppm!!

OK. In that case, you want to have the nitrates in the range where you have difficulty differentiating between 10 and 20 (or even 5 and 10 - where mine runs) rather than between 40 and 80. :)

Certainly get it in the 20-40 range right away..

[FishInMaryland]

OK, this morning I've done a 50-60% w/c and phosphate is down to 2-5 ppm, and nitrate is down to 20-40 ppm. I'll do another w/c on Thursday. I didn't do anything with the filters, since I cleaned one 2 weeks ago, and almost had a flood with #2 this morning. The old-old-style Fluval external canisters are a pain.

I still don't know about lighting. I've read that more light will help discourage algae growth, but people who have outbreaks almost always immediately go to a lights-out situation for a number of days. Any thoughts on wattage and amount of time to leave them on?

[zazz]

I'd suggest leaving the lights alone for now and concentrating on maintaining low nitrate /phosphate levels.
I say this for two two reasons.
For one thing, I suspect it will solve your problem, given some time ( 6 weeks?thats a wild guess)
secondly, it makes sense to change only one parameter at a time in order to learn whats really going on, which will be good for future.

[mooman]

I agree with all advice so far. Nitrates are too high, have you tested your well water for nitrates?

If you have no live plants, then I would turn the lights out all the time, except when viewing (few hours in the evening). Is there any sunlight leaking into the tank? It also might be worth noting that an algea problem to some people, might apear normal to others. Everyone has there own tolerance for that sort of thing. I noticed that you didn't mention any algea control fish. Even with my weekly 40% water changes, I still rely on ottos or rubber plecos to keep the tank looking spiffy.

Also , have you thought about anubius, java fern, bolbitis, jova moss. These are live plants that you would be hard pressed not to grow and when arranged properly can look fantastic. There is a 300g planted display tank at my lfs that people are always saying "wow, I bet you need alot of light for that" . Well there is alot of light and co2 on that tank, but on closer inspection 75% of the plant mass is made up of the plants i mentioned above artfully arranged to showcase a very few "high maintainance" plants. Just about anyone with a 1-2 watts/gallon could come pretty close to duplicating it.

[zazz]

oh yeah, moonman makes good points. if you have no plants you dont need Any light LOL
I am also an advocate of java fern/ java moss. but You seemed pretty dead set against plants. But i have nearly always had very good results with these. NO extra light No extra fertilizer, No co2.I dont know how much difference a nice big java fern will make in your nutrient levels, but better than nothing. Plants Are the only other way to remove nutrients beside water changes.

[FishInMaryland]

The well water is low in nitrates. I've tested the tap, and it comes up less than 10 ppm - don't remember exactly.

Am pretty set against live plants, b/c the parrot cichlids are voracious eaters and big diggers. What doesn't get chewed up ends up floating. Plus, our well water seems devoid of the necessary nutrients, so I had to dose, which is HUGE trial and error. I tried many many different plant varieties, and for 8 months had no success with anything. My initial thoughts had been exactly what you suggested...lots of plants to use up excess nutrients. The tank came with Java ferns initially, and they died rather quickly. So, although you don't add extra fert, your tap water must have some minimum amounts - mine apparently has none!

Lights - since I took out the live plants, I have just had the lights on for 2 hours, after I come home from work. There is a teeny bit of direct sunlight, about 1-2 hours' worth, that hits part of the tank in the morning. Otherwise, it's pretty dim in there.

I will leave all as is for now, and take your suggestions to just work on one parameter at a time. Right now, it's water changes/filter cleaning. Thanks.

[janderson]

about two hours each day in the early afternoon about 1/3 of my 37G gets direct sunlight. Which I didn't mind, this being a planted tank I figured some extra light wouldn't hurt. Well, algae took off: it started where the direct light hits but quickly moved to all areas and surfaces of the tank. While cleaning the glass every few days wasn't a big deal, it was near impossible to get it all off the plants/rocks.etc. without constantly rearranging the whole tank. So I ended up introducing three otos: it took them about three days to get the tank clean and it's been clean ever since, they're doing a great job!

[FishInMaryland]

Oh yeah, I forgot to mention that I had a bristlenose pleco who I had for a couple of months, then he just died. He rarely moved from the spot he claimed next to one of the heaters, and I didn't see anybody pestering him, but I never saw him moving around (day or night), so I'm not sure if he starved or something else. I've been thinking of some algae-eating fish, but am afraid to upset the current balance, such as it is.

[zazz]

sorry to hear about your pleco. maybe it wasnt too healthy to begin wwith?
I didnt suggest al;gae eatingfish because for one thing, i dont kow which ones like the type of algae youhave. would be a good thing to look into , i suppose, while you are waiting to see if reducing the nutrients and cleaning the filter helps.meanwhile smart to not add new fish untill you get the nitrates etc in order.
I am guessing that janderson had green algea and You probably know more about the difference between that and brown than i do.
All in all I strongly suspect that rtr has called it and you will be happy following his advise.
the simplest explanation of too high nitrates in your tank as far as i know is insufficient water changes. along with the nitrates, whoknows what else was accumulating inthere.
i am expecting good results from your new course of action. keep us updated, ok?
thanks

[FishInMaryland]

Here's the update:
I did 2nd w/c for the week today. Several hours after, phosphates are about 2 ppm, nitrates are close to 10 ppm. I also replaced the foam in filter #2, since the old stuff was pretty gunky. I know I could have just rinsed it out, but with the redundancy with the filters, I figured it would help lower my nitrate & phosphate levels to replace it instead. Keep your fingers crossed. I'll check the levels throughout the upcoming days, and see what the w/c frequency needs to be.

How do I know how much water to change at a time? Say that the nitrate level goes up to 20. How much water (percentage) do I have to change to bring it back down to 10? I know I should be able to figure this out, based on my w/c this week, but my brain isn't cooperating.

[RTR]

50%

I change from 33 to 50% weekly in my tanks.

For more info, see: http://www.thepufferforum.org/viewtopic.php?t=1326

[FishInMaryland]

Update:
10/11 - 60-70% w/c & vacuum gravel (not very dirty, since I have a pretty bare tank and can swish it around thoroughly on every w/c)
Nitrate 20-40 ppm, Phosphate 2-5 ppm after w/c
10/13 - 60-70% w/c, cleaned filter #2 and replaced all 4 sponges in that filter
Nitrate 10-20 ppm, Phosphate 2 ppm after w/c
10/16 - Nitrate 10 ppm, Phosphate 2 ppm, Ammonia .25 ppm
10/22 - Before w/c, Nitrate 20 ppm, Phosphate 2 ppm
50% w/c
Nitrate slightly under 10 ppm, Phosphate .5-1 ppm after w/c

I had more brown stuff than I would like that still has accumulated on the driftwood and on the leaves of the silk plants.

I haven't changed anything else from the original tank specs shown above. Is this normal, or should I try to do something else? If so, what do you suggest? Any changes to the lights?

Thanks for all of the suggestions thus far. I'm encouraged enough to consider getting another (smaller!) tank (once I've got this one licked).

[RTR]

It sounds like you have it down now, just monitor your changes a few weeks as you have been doing to find what it takes to keep it down. keep an eye on the diatoms while the tank is operating at lower nutrient levels. With any luck they will fade a bit, or not come back so quickly with water cleaner.

[FishInMaryland]

This is perhaps a ridiculous question...

It occurred to me that I have 2 empty media chambers in each of my two Fluval 404s. Would it help to keep the nitrates lower, and from increasing as quickly, if I were to add more ceramic doodads into each filter, to increase the size of the bacteria colony? I thought my original problem was phosphates, but in hindsight, I think it was the nitrates.

Thanks.

[RTR]

Nitrates are the tank end product of nitrification, as the much less harmful oxidation product of ammonia and nitite. You do not want to hinder nitrification or you will kill your fish.

You produce less nitrate by lowering your stocking level, feeding carefully, having lots of live plants, and/or doing more water changes. The last is the most certain technique.

[FishInMaryland]

I knew there was something I wasn't thinking through. I just couldn't see that the amount of nitrates, by the end of the nitrification cycle is a direct result of the amount of ammonia that starts the cycle. Output is based on input, in other words, and the amount of bacteria that makes this happen will not reduce the amount of output. Right?

[RTR]

You got in one! Input equals output, but the nitrate output total weight is more than the ammonia total weight input. That because ammonia is lower weight than nitrate, three oxygens added and only one hydrogen removed. If you tracked it on nitrogen only, it appears to balance more rationally beacuse it only one N at each step (which is why ammonia-nitrogen, nitrite-nitrogen, and nitrate-nitrogen are sometimes used). The nitrification bacteria cannot produce more than what has been released in the tank by all inhabitants, and that is their job and why we try to protect them..