Serious Problem

Water changes?

what is your water change schedule?

How old is the food?

What was the newest fish added and when?


How are the Oscars doing?

skip the live tubifex, it's a real easy way to get internal parasites. that possibly may be your problem, but i doubt it. do the scales stand out? sort of looks like a pine cone? then it's dropsy, an internal bacterial infection. at that stage it's probably terminal unfortunately.

skip the "cycle" too, that is snake oil. that actually might be causing the problem. having an over-abundance of bacteria in the tank. no one has been able to prove this stuff really works either. and we have had several long discussions here about it with no real answers. the bacteria that actually control the "cycle" in the tank really can't be effectively bottled..... so instead alot of those companies give you a "waste eater" bacteria that somewhat mimics the cycle until the cycle bacteria grow. water changes work much better and cost alot less.

i'm going to guess tho, that maybe the snail dying was the real root. when it died the fish ate it and got the problem from it .... maybe.

the best bet is several large water changes and cross your fingers unfortunately. you could try a bacterial cure if it is dropsy tho, but don't expect alot, dropsy is VERY hard to cure. the best bet with dropsy is to humanely destroy the fish and dispose of them, NOT to other fish, as that will help pass it around.

it's a tuf call, but from my experience dropsy seems to be most common in newer tanks when the bacterial levels are going a bit haywire. it is a bacterial infection of the internal type and sadly, what you are seeing when the scales start to stick out is the internal organs starting to fail. specifically the kidneys, then the fish starts to retain water, hence the swollen body.

breaking the (sickness) cycle now is important, you don't want other fish to eat the dead sick ones. you could also try using something like tetracycline or penicillin to decrease the bacterial levels in the tank, but this might set your cycle back a bit.

argueably the best bet might be just to try to ride it out. keep doing your water changes, maybe a slight touch of salt in the water.... and hope for the best. if things get worse then definately use meds of some sort.

a fish's immune system is a powerful thing, the problem is, during the cycle and adding them to a new tank it gets depressed (the immune system). the fish get stressed and it lowers their immunity. so the best solution to this or any other problem is making the fish happy basically. outside influences such as moving them and poor water quality are a bad thing and will cause problems.

check your water parameters also, the yellow tinge suggests to me that your cycle is a bit out of whack at the moment. at the least, something is wrong with your chemistry, the tank is not clear. even green water should be clear in a balanced tank. discontinue using any chemicals besides the basic dechlorinator and possibly some salt and do some extra water changes. that will help give your fish a cleaner environment and help them be less stressed (and more immune). run a gravel vac now and then and remove any other fish that die. if they get bloated with dropsy you might want to consider freezing them or otherwise humanely destroying them so the other fish don't eat them and spread the infection more.

don't chemically mess with the ph. if you need to raise it then try a small amount of crushed coral in your filter or something. shells will also help a bit. what is your tap water ph? if your tank ph got really low, it also might have affected the cycle. if it gets down to 4 or 5 the bacteria will die. i forget exactly what ph the bacteria die at tho, unfortunately.

in a couple weeks or whatever, when the tank stabilizes you might want to look into an algae eater. oto's might work for this, but they are notoriously touchy so expect a death or 2.

the oscar should be able to resist getting the infection if it's healthy.

live food isn't a neccesity. live food can become a liability alot of times, as it's very easy to introduce nasties with the food. a variable diet is good tho. so using flake one night and crumbles another is good, some sort of vegetable matter is also good. frozen food is also very close to live and can be bought in serving size pieces. freeze dried is ok too. if you insist on live there are brine shrimp hatcheries or even maybe something like regular earthworms, or maybe you can get bloodworms from a bait store. it's just tubifex is known to carry parasites..... freezing or drying kills them.

good luck

n/p we were all new once.

i'd take the crushed coral route. find some way to put some in the filter or tank. maybe a baggie in the filter...... it's not an exact science, so you will have to experiment a bit with amounts. maybe a couple tablespoons to begin with. eventually it will have to be renewed too, as it leeches into the water it will disintegrate. some people actually use it as substrate, but that's for hard water species like rift lake cichlids.

this should stabilize your ph and raise it a little. also prevent any ph crashes. the nitrogen cycle will make the ph drop a little between water changes normally, so that should help quite a bit. it also raises the buffer in the water(kh), which stabilizes the ph and prevents crashes.

in an emergency you can use baking soda to raise just the ph, but this also is inexact. mix a little bit into water change water and probably test. then add the water to the tank. you don't want to make drastic ph changes quickly tho. i would do no more than a point (1.0) in several hours. ph shock can kill fish pretty quickly and it will occur at jumps of over 1.0.......

it would take a little extra work, but you would get used to it after awhile and it would become pretty easy.

good luck