first signs of fin rot

[dmarcus]

hey i recently got some angels for my 29 gallon community tank and a couple days ago i noticed that three of them have what appears to be the first signs of finrot. The tips of their dorsal and anal fins appear to be slightly shredded and white. Non of the other fish in the tank appear to be suffering from it but i dont want it to get any worse and i want to be able to treat it. I do have a quarantine tank set up cause i have shrimp in hte 29 gallon and htey are super sensitive to medication (i found out hte hard way). Anyway i keep the tank at 77-79 f, ph is between 6-7 (i add 2 drops of ph down/gallon) ammonia nitrites 0, and nitrates usually steady around 20 even after water changes (i think its my tap water). I have read that overcrowding can be a cause as well as stress however my fish dont really act stressed and exibit normal behavoir from day to day. I do add aquarium salt with water changes, 1 tablespoon/5 gallons, so if anyone can give some suggestions as to why they might be sick or any possible solutions i would appreciate it. Thanks in advance fishforums.

[Zoe]

How long has your tank been set up for? Did you cycle it?

You tank is definitely overcrowded. It is recommended that a pair of angelfish be kept in no smaller than a 30gallon tank and to that I would only add a school of small tetras. Obviously there is some flexibility if you keep your water crystal clear, but with 3 rams, 4 angels, 5 rainbows, yoyos and plecos, that's a pretty heavy bioload. It's not urgent but I would suggest that you look into upgrading your tank sometime soon, or bringing back some of the fish to your LFS. Finrot does happen but in a clean, properly cycled, properly stocked tank, it should be a rare occurance.

The stress from overcrowding or nitrite build-up (what's your nitrite level at?), could have encouraged the finrot. Are the angelfish in your QT right now, you mentioned you just got them? If that's the case, treat your angelfish (a good antibiotic is chloromycetin (chloramphenicol) or tetracycline). Or move your affected fish into QT and treat them. If too many of your fish are affected or if your QT is too small, put your shrimp in your QT and treat your main aquarium.

Salt is benficial at this point but in the future, healthy freshwater fish require no salt in their water.

[pokagon55]

Fin rot happens when there is a stress in the tank,take care of the stress and the fin rot will go away. I have to agree that your tank is overcrowed but it could also be from the move from one condition to other because as you stated you just got them, so it might be they are stressed from the move and maybe the differnets in water conditions. A ph of 7 to 6 is pretty big and adding a chemical to lower ph is always frowned on. It is better to have peat moss or bog wood in the tank to do the job. Regular adding of salt is not needed with freshwater fish as it can cause a problem with osmosisregulation of the fish which can lead to a added stress for the fish. The number one cause of fin rot is water condition, you never said how often you change the water? When the tank becomes overly stocked it is best to do water changes more often to cotrol and maintain the quality of the water, also adding a extra filter woundn't hurt either as to make sure enough oxygen is in the tank for the extra fish.

[dmarcus]

i change my water every sunday by about 30% (2 5 gallon bucket fulls) and like i said my nitrites are 0. The tank is mature as has been long cycled, i agree and think that my filtration could be better i am using an aquaclear 50-70 gallon filter and i just have it turned down all the way. At one time i did have some malaysian driftwood in there to lower ph, but i recently took it out for astetic (not sure how to spell it) reasons. However looking at my fish now it seems that whatever fin shredding had occured it has now stopped, but i will keep an eye on it to make sure it does not continue.

Another question how much is the bioload affected by hte size of the fish cause all these fish are juveniles and do not get much larger than 3-4 inches. Plus the school of 5 rainbows adds up to a total of 5 inches, they are tiny. I have always heard that 1 inch of fish per gallon of water. Anyway im sure someone will correct that statement but i set up that tank with that in mind, if you wanna see some pictures of it look in the aquarium photos and see my post called planted 29, thats my tank but it took out the driftwood on hte left and added some jungle val plus java moss and varios other plants. thanks everyone.

[Zoe]

I agree that chemically lowering your pH is not the greatest idea. Use peatmoss (you can put a layer under your regular gravel).

The 1 inch per gallon rule is very general and is a "beginner" rule that doesn't always apply. It's a starting point for beginners. There is no mathemetical forumla that will determine what you can put in your tank. For example, if your 29gal is a tall tank, there is considerably less surface area for gas exchange. Also, you state your tank is heavily planted - this means there is substrate / gravel, plants and other decor taking up probably several gallons of swimming area. In addition, angels only get 3-4 inches long. But they also get 3-4 tall, plus their fins. And there are fish like plecos which are huge bioload, relatively, for their size. Your 3" of clown plecco, for example, is equivalent to maybe 8" of neon tetras.
Anyway, it's all about balance Filtering / water changes / total amount of fish, it's all an art, lol. Seeing your stocking list, I think you would have healthier, happier fishes if you got rid 2-3 of your angels and maybe one of the rams. But for the time being, like pokagon said, get another filter, maybe an airstone to provide enough gas exchange and oxygen for your fish.

[pokagon55]

I really like the 1 inch per gallon rule as it is the best place to start until one has the means to understand how this hobby works. Glad to hear that they are doing better and I think that maybe it was an adjustment issue as Angels are sensitive fish. I'm still a bit concered with the amount of oxygen entering in your tank, even with the plants, at night plants can rob and consume oxygen from the tank causing oxygen depletion which will cause stress on the fish. Still, this tank sounds like a great tank and over all no other things I can come up with other than maybe a bit over stocked and low on o2.

[PlatyLady]

I have to say that stocking your tank takes more than just a rule of thumb, though that's a great place to start. I think I agree with Zoe, in that the bioload may be greater than one might think with the types of fish you have. At the same time, however, for the longest time I kept the fish listed in my signature all together in one 5 gallon tank, and I never had any problems with stress or tremendous bioloads. Everything was absolutely ideal-pH was perfect, zero ammonia nitrites, and great nitrate levels. The only reason that I think the tank thrived like it did was because I keep the oxygen levels way up there. I always have at least one to two bubble curtains and one decorative aerator going at any given time. Maybe try keeping the O2 pumping to keep everyone happy