What am I doing wrong?

[SpyderSpy6]

I did a water change today and all of a sudden things went wrong in my tank. I have a blind discus that I'm keeping in a 20 gallon right now, and when I did my water change him and the 2 cory cats became sick.

They are not really moving, not eating, and hanging at the bottom. I don't know what I could be doing to cause this, but it's the second time I've done this, and I've read on the forum of other members having somewhat of the same issue. There are only two possible variables that I can think of...

1. Among the R/O water I use to change my tank, I used a small amount of tap water to fill the top. This was dosed with discus buffer and tap water conditioner. Is it something the city is putting in the water???? but with such a little amount added, how could this cause the entire tank to crash.

2. I used Blackwater Extract. If you use too much of this will it cause problems? Or can age change the make up of the additive?? I didn't exactly measure the amount, and it has seemed to linger in the tank longer than I would like.

These are the only two factors I can think that have been different. As soon as I noticed this happening I changed the water (about 6 hours after my original water changes) with only R/O water, but some of the extract seems to be in the water because it has stayed that brownish tint.

I need to figure out what I'm doing wrong. I feel like I do everything the same (plus or minus an additive, but I'm not trying new additives) and it just goes downhill for no reason. Luckily this is in my 20 gallon and not my 75, so medicating won't be an issue. I did dose Maracyn I & II because it helped the last time this happened.

This is probably one of the most frustrating things I've encountered in my fish keeping days.

[mister]

I think your problem is the same thing it's been in the past; Way too many water changes and way too many chemicals. Your tanks are never stable.
Let your fish adapt to local water. RO water, constant changes, and excessive dosing, etc is a recipe for instability. That instability equals stress.


Tap water treated with NovAqua, a 40% water change every other week, and bi-monthly plant fertilizer is all I ever do. It's given me very stable tanks and long-lived, healthy fish (including Discus) for more years than I can remember. I sometimes change water every week for a month or so after I've added new fish, particularly if they're Discus. I only really do it as a precaution and it may be a waste of time.

Stability and a stress free environment are key in my world and have served me well.

[Drip Loop]

I have never owned a discus, but from what I have read, these fish cannot "adapt" to just any water condition like other fish. I was under the impression that these fish have specific water requirements including low PH, warm water, and water with few impurities. If I am wrong, than someone correct me. I only know what I have read.

[Lady Hobbs]

R/O water softens the water as well as the Black Water Extract and then you're using buffers besides? You may have lowered the pH too much. R/O half and half with tap water should be fine or if using just R/O, you should be using some water supplements as all R/O is lacking in electrolytes.

Sometimes we should not fix what is not broke. Let your fish get used to what you can give them naturally. Possibly some almond leaves in the tank but forget the chemicals.......especially if you are just dumping them.

[Fishguy2727]

Some types of discus are more adaptable than most give them credit for. They can breed in a pH as high as 7.6. What they, and really all fish, need is water QUALITY and STABILITY. They do not need a pH of 6.5 or less, they don't need it super soft.

This may not be true with wild caught discus or ones from breeders who go crazy over them (pH of 6.0 or less, daily water changes of 90%, etc.), which is why I don't recommend those types of discus to anyone.

[SpyderSpy6]

I know it seems that I'm dosing too much... but here's the thing... I've only been doing my water changes with pure R/O with added equilibrium to put minerals back in it. I let that sit for a day and then I use that water to do my changes.

The ONLY water I put the discus buffer and black water extract in was the tap water that I used to fill the rest of my 20 gallon, and that was to help even it out with the R/O I had used previously.

My 75 gallon is thriving and my fish in there are gorgeous! The fish that this happened too was a blind discus I had adopted from my brother and I was keeping him in a 20 gallon. I've had him in there for about a month and this was the first change of water for him.

Unfortunately he didn't make it. I think it was a combination of the fish being malnourished and with this hitting him he couldn't handle it. When I took him he was very very skinny. I just don't know how doing a water change could throw everything upside down like that. It's not like I dumped an entire bottle of black water extract, nor did I dump a handful of buffer... it was a little more than a cap of black water, and not even a half teaspoon of discus buffer. This should not disrupt the fish tank the way it did.

[Fishguy2727]

Did you check the tank water's parameters before and after? Did you check the parameters of the water being added? It may not seem like there should have been a problem, but without testing there may have been a problem that should not have been there.

[kaoticice]

Ditto with the majority of the suggestion. Too much water change, and lack of stability in water chemistry. This is just my guess!
Some fish tend to be stronger than others, and that's just like us some of us have stronger immune system while others don't. As you stated, that the discus wasn't really in its perfect condition initially, maybe a slight swing in the water chemistry made a big impact on it.
I actually did a little experiment on 2 betta's in a 2.5gallon each, one gets 80%wc and the other gets 30% wc a week (im not using age water). Every-time i did the water change I notice a behavioral change with the betta i did the most wc, he seems a little quieter than usual and did not accept any food for at least the next couple of hours.
I like to recommend doing about 30 - 35% wc a week per tank, and try to avoid chemicals that are likely to swing water chemistry around. As stated, fish can generally thrive and tolerate in wide range of water chemistry. "Stability is the key".

Hope that helps, and sorry for your loss
Ed