Disturbed sand - fish dying??

A fellow discus keeper in Sweden has some serious trouble and I'm reaching out to you for advice so that I can help him.

He bought 12 adult discus a couple of weeks ago and put into a 150 gallon planted tank.

In his eager to keep the tank clean he tried to vacuum the sand the other day and disturbed the sand a lot.

Today several fish are dark and swimming sideways, looking out of balance and weak.

I've told him to do large water changes and aerate well.

Something else he should do? He has an empty 40 gallon tank. Should he move them?

From other hobbyists in Sweden he gets the advice NOT to change water, and that his earlier large water changes has caused the sick fish. Now he is not sure who is right so I want your opinion to refer to!!

I think you gave him the best advice. Were the fish sick before he did the large water change?
Pat

Thanks for your involvement Pat. I know you are very experienced so it is good hearing this from you.

They were healthy when he bought them a couple of weeks ago and two even spawned immediately. The fish are from Piwaworski but has been in a planted tank at the lfs from what I've understood.

Last week I think two fish started hiding in a corner / behind plants and not eating properly.

He was doing very limited water changes up to this point, like 50% a week at the most, in a planted tank, non co2. I told him that he should do more frequent water changes because it's hard to maintain good water quality in a tank with substrate, and maybe that is stressing his fish.

So he did, but unfortunately also thought he could clean the sand and disturbed it a lot.

Now other people are telling him that the water changes stressed the fish out, and that it disturbed the bacterial balance of the tank... And that he should quit changing water.

Of course it's hard for him to now who to listen to.

Quote:

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Originally Posted by Second Hand Pat

I think you gave him the best advice. Were the fish sick before he did the large water change?
Pat

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Changing 80% often seems like a no brainer. But I'm not experienced enough to tell him whether he should move all the fish to the empty 40 gallon or not.

The two largest discus still seem ok.

It is a bit hard to place 12 adult discus in a 40 gallon. I think they will be worse off with the ammonia, nitrite production.

Quote:

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Originally Posted by Second Hand Pat

It is a bit hard to place 12 adult discus in a 40 gallon. I think they will be worse off with the ammonia, nitrite production.

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Ok. I did not however mean permenantly, but only as a way of helping the fish recover as they now look like they are dying. But large water changes in the planted aquarium is better then?

I would continue with the large +80% daily WCs in his main tank with aged water Jorg.
12 piwo adults in a 40 g is a thin ice as Pat already warned.
If he can get the plants and decor out , siphon out the sand partially via siphon with every WC and get to BB in a couple of days it would be even better , at least until the fish recover .

You said a week earlier some of them went dark and skittish , so my guess is that previous low maintenance lead to discus lowered immunity and catching some disease even before the event of deep sand vacuum.

I'm curious if the other hobists who advise no water changes are discus keepers at all , or just random fish keepers ?

Avoid searcing answers about discus on regular fish forums .

Like mentioned the discus may have been sick when purchased.I would highly suspect this since new fish/stock are coming and going all the time in a fish store.An easy place to bring home an infection;just like humans visiting a hospital.Also when disturbing the substrate that hasn't been cleaned in a "while",could lead to this:::http://www.aquariumadvice.com/forums...or-147656.html