Discus suddenly died after water change

[Sarretty]

I recently moved from florida to colorado. I have a 90 gallon planted tank with two canister filters. (overkill) I do a small water change during the week and a large (over half) change on the weekend.

I HAD (6)2.5-3" discuss three bushynose plecos 20 cardinals and two rams in the tank. It is pretty heavily planted already.

This tank has all new gravel and was running for a month before I received the discus. The discuss have been in the tank healthy bright and happy for the last 3 weeks since I received them.

Yesterday evening I did an approximate 65% water change. I added tap water with the python water hose and used dechlorinator. I observed them for a few minutes and all seemed well and then didn't see the tank again until this morning.

This morning 3 discus where at the surface dead, ones stomach actually swelled and burst. Two others where on the floor and one is still alive but at the surface of the tank.

The cardinals where all at the surface too with no losses there. I also notice the plecos surfacing more than usual.

Nitrates and nitrites are all minimal. Ph is in the high end.

But it all seems to stem from the water change last night. There where not any issues until then.

One note is that it seemed that they went to the surface after one of the other water changes too until input in an airstone to agitate the water. I removed it with no issues after about 24 hours. Also I did notice the discus stomachs appeared fatter last night but I had just fed them and they where pigging out.

I feed them a mix of beefheart flakes vegi flakes and bloodworms.

Does anything stand out? Have you heard or experienced this before? I'm not sure where to go from here.

I appreciate your assistance and time...

[bruinsbro1997]

What's the ammonia level?

If the pH was high it could've killed your discus. If it was soft beforehand and somehow went alkaline during the water change it would kill them, real big changes can do that to any fish.

How long was the tank established and cycled beforehand?

[Sarretty]

[QUOTE="bruinsbro1997"]What's the ammonia level?

Nitrites where below 0.5

The tank was cycled for a month and was started with eco complete gravel. I sprinkled tips of food in a few times to get it ready. There weren't any issues until this last water change. (curious for learning purposes why you ask about cycling)

Also I didnt test immediately before the change for hardness. But the water is from the same source. Would this fluctuate over time?

I appreciate your response.

Also with an airstone and more agitated surface (from water return) and some aquarium salt all the fish seem to have returned to normal. The one discus seems a bit stressed still. Could the oxygen been an issue?

[Flossie]

I would test my tap water just to see if anything has changed.... Ph... Ammo levels ( chloramines ) etc... Just incase.

What water conditioner are u using ?? And what was the tanks ph before the
Water change and after ?

[karen21]

Hey, I'm new to this, but 65% water change?
I know these fish need clean water, but that sound very stressful.

[LyndaB]

Is this the first massive water change you've done since you moved?

[DragonFish71]

What part of CO are you in?

I can tell you right now that most of our water is very high pH. Higher in some parts.

Also, this time of year most of the water municipalities are adding extra chlorine or chloramines in the water treatment process. All summer long is considered melt off/ run off. Either the snow is still melting up in the mountains, or we get a heavy rain or two that causes minor flooding (like the one we had in my town this week) All that extra water flowing into the drains brings bacteria and who knows what to the water treatment plants, so they beef up the chemicals. Not to mention all the dissolved minerals from water coming down the mountains.

Your best bet with CO water and overly sensitive fish is to fill buckets a day or 2 ahead of when you're doing a water change that way they can gas out, then use them for the refill water. Or go with an RO/DI unit.

I also always add extra dechlor, I use Prime because of the extra chlorine used in our water.

[Sarretty]

I live in Colorado springs... That makes sense about the water. I have since purchased a clean plastic barrel to age the water in... A heater and an airstone and a water jet to move the water around should do the trick. I was oblivious to the additional chemicals etc. Thank you very much for the advice.


These are not the same fish just the same setup. New gravel too. Te water changes are nothing new to the tank. I do two water changes each week. One is a 25% and a little over half water change each week.

[LyndaB]

I'm very sorry for your loss. Discus are such a beautiful species.

[Sarretty]

Dragonfish... How do you work your water changes then? Still strait from the faucet but add the extra dechlorinator?

[DragonFish71]

Originally Posted by Sarretty

Dragonfish... How do you work your water changes then? Still strait from the faucet but add the extra dechlorinator?

It depends on which tank, if their very sensitive fish or not.

For most of the tanks, yes, I fill straight from the faucet with my python and add the Prime (plus the extra) as it fills. I use airstones on most of my largers tanks so that with the water filling helps circulate it around. I also add Stress Coat if I have any on hand.

For my sensitive tanks, which are my RCS and pygmys, I use 1 gallon milk jugs. Since those tanks are smaller 10g and 20g, it's easier. I clean them every other week (very small bio-load). I do with the milk jugs like I suggested with buckets. I fill them, put in a few drops of Prime, let them sit uncapped for a few days, then cap them and they're ready for next time.

[jetajockey]

Originally Posted by Sarretty

Nitrites where below 0.5

The tank was cycled for a month and was started with eco complete gravel. I sprinkled tips of food in a few times to get it ready. There weren't any issues until this last water change. (curious for learning purposes why you ask about cycling)

Also I didnt test immediately before the change for hardness. But the water is from the same source. Would this fluctuate over time?

I appreciate your response.

Also with an airstone and more agitated surface (from water return) and some aquarium salt all the fish seem to have returned to normal. The one discus seems a bit stressed still. Could the oxygen been an issue?

Sorry for your loss. Discus are very sensitive, that .5 nitrite reading could have contributed to the problem as well.