Bad Advice From Pet Store Has Cost Me 3 Fish So Far. Help

[marshallr]

I am in dire need of help. I have had a 39 gallon fresh water aquarium set up for 2 years. My tank has been thriving, no fish loss, steady ph , 0 ammonia, 0 nitrates 20pp nitrates. No problems. I had 3 angelfish, 3 glass catfish, 2 tetras, 2 platy, 1 rainbow shark and a couple of live plants. I have had the angels since they were babies and are now very large adults. The others have also been in my tank for over a year. I added another baby angel and a glass catfish recently. The angel died within a week. When I went back to petco they tested my water and said my ph was low and nitrites high. My ph has always been lower than most recommend but after reading several forums and books I found a steady ph was more important than being 7. It was 6.4. Well, the guy there said i needed to raise it or I would continue to lose fish. He said to add 2 bags of crushed coral. Unfortunately, against my better judgement I did. Now 1 of my angels has died, another looks as though it is not doing well, a tetra and a barb have all died. I tested my water and the nitrite was high, ph now 7.6 ( he told me it would SLOWLY raise my ph , not true). I took out as much of the coral as I could , did a 30% water change. Can anyone give me ideas on how to save the remainder of my fish, more specifically my angels? I am devastated over the loss of one, after raising it from a baby we were all attached.

 

[ripil]

yeah adding coral rock would not raise the pH slowly at all. it would go up quite quick and stay at an even reading which would probably be to high for the fish your keeping. imo the fish you got was from bad stock if you've been keeping fish along time with no dramas. not to sure but i think major water changes would lower the pH once you've got all the coral rock out but i'd wait to see what other ppl say first too. did you add anything else that could of effected the pH level? if so i'd take that out too as a reading of 6.4 is ideal for your fish. the two tetras really didn't have a chance to be fair as they live to be in large groups for around 10+. the pH changing a bit, in my experience of keeping them, would of killed them off in 48 hours or so. their water conditions need to be really balanced. a little bit of coral rock would stop your pH from crashing but i wouldn't advise you on how much to use in a 39 gallon tank as i don't know. hope this kinda helped.

 

[TwoTankAmin]

It was not the coral, it was the nitrite if that reading was correct. The next thing to suspect was the fish you added, which you did not quarantine, brought in something with them. You do not describe how the fish that died looked or behaved before they died or after either. So its hard to deduce much without such info.

I use crushed coral to raise my TDS. I can fill the baskets in two H.O.T Magnums (way more than you can fit in two bags in a filter). I run them for about 16 hours on a 20 gallon trashcan and the result is a TDS rise of about 18- 20 ppm. This should not have killed your fish. And TDS changes are much more deadly than pH changes for most fw fish.

I also tend to doubt the accuracy of the pH readings here, especially at Petco. What I do know is angels can do fine in pH 6.5. (Mine spawned at 7.4.) So can the shark and the tetras. They do prefer softer water though. However, the platy prefers a higher pH and harder water than the rest.

Taking the coral out and the water change would cut down its effects. But if I am right and the problem came in on the new fish, this won't help much. If its the elevated nitrite, then water changes will hhelp with that. Or else get some Amquel+ which will detoxify nitrite as well as ammonia. Other dechlors may also do the same- prime for one should. I have well water so don't use them much.

You need to have your own test kits and use them and not trust PetCo. Ammonia, nitrite and pH at the very least. And even though you wont normally use the kits much, it helps to know hardness (GH) and KH. The latter is buffering and it is intimately intertwined with pH.

 

[snazy]

To be honest, all of these together could have been the cause for what happened.
First, high nitrItes can kill any fish or at least weaken their immune system so they can't fight external bacteria/parasites. Second, the Ph was played with at the same time when fish might have had weakened immune system due to the nitrItes and just couldn't manage fight it off. Third, even though it's not necessary for fish from the LFS to be sick, they may have been carriers(this doesn't mean sick) of some bacteria/parasites that your other fish are not immune to and the changing conditions didn't help any of them fight it. This works both ways.

How did you acclimate your fish?
And if your own fish were happy for 2 years in such a low Ph, then I wouldn't have bothered changing it and is probably not the reason the new ones died. More than likely you just need to use drip acclimation for a good bit of time for new fish in the future.
I don't know what everyone else says but not every fish will survive a sudden TDS change. If someone was successfull, others may not...If it were true that a change in TDS does not affect fish, we would have been able to just throw a fish from the river straight to a tank without any ill effects ever. Also, in a 39G tank I wouldn't bother adding fish that grow big like the angels or the sharks.