Fish acting like their dying after a water change

[BettieL]

I just did a water change on a my 75 gallon mbuna tank. I did a 50% water change, last water change 11 days ago. I'm on a well so no chlorine to worry about. I have a sand substrate which is fairly new about 3 weeks old.

ph 8.2, hardness on one of those sticks is top of scale. No ammonia, nitrites 0 nitrates barely readable. water temp 78 degrees. I have 10 yellow labs, 8 rusties, 6 cyno axelrodis, and 8 afra cobues in tank, 2 bn plecos.

before water change they were acting great, after water change they all started acting like they were going to die. Laying on sides on bottom, gasping rapidly, swiming straight heads up. Then laying on sand on sides like dead. You go to touch them and then they'll move. I can catch them easily with just my hands.

No filter changes/cleanings were done, just a simple water change. Usually do 40-50 weekly/10 day schedule. Previously no problems with this tank. I had a small 29 gallon that the afra cobues were in did change on that 4 days ago and they did this same thing to me. Moved them to big tank and they recoved in 5 min to normal.

This is driving me crazy don't want to lose them, their all juvies in the 1 1/2-3 inch max sizes.

[Timber317]

Add some prime if you have some!!

[fshfrk]

I would say co2 lowering your ph. What is your location?

[BettieL]

No Co2 in tank its a mbuna tank, no plants. But they did act like they were suffering from O2 depravation before they would fall to floor of tank. No prime as were on well water. Lost 2 of the bigger ones (2 1/2 inches) didnt get them pulled out fast enough. Put them in another tank, (40 gallon) that I had also just did a 40% water change on and they are all recovering. Only fish left in 75 gal is the 2 bn pleco's as it doesn't seem to be affecting them as much.

[JAYGEE]

How big a difference in water temp?

[BettieL]

Exact same as i used a thermometer and double checked it 3 times while filling using a python water changer

[crazy42bmx]

Id re-test ur well water and get some prime , just in case !

[cichlidomaha]

I would add a powerhead or two for extra circulation and add prime even though you are on well water just to be sure it could not hurt. It would also help to put a large sponge filter with a decent size air pump running it, to break the water surface with air for extra oxygen. This should help. How much and what type of filtration are you running? I am thinking it may not be enough.

Tom

[jughead]

what kind of aeration do you have?we had the same problem sometimes doing water changes.we have a well.was mostly affecting mbuna.a fish farm guy said it was too much nitrogen in the water.increased aeration in the tanks,problem gone.good luck

[BettieL]

Already have a power head on a sponge filter sized for a 125 gal tank and a magnum 350. had the 29 gal with cobues act same exact way. Only similarity between the two tanks is it was first water change after changing substrate from gravel to sand.

[troy tucker]

What tipe sand?

[BettieL]

It was sand i got from sand deposit from a wet weather creek on our land. It was nice and clean and i rinsed it well. They did fine with it when first put in only after that first water change did problem come.

[JIM]

i get the same issue, figured out it was low oxygen levels out of the well water. I now refill making the sure the returning water is above the waterline to help wit aeration. and also hang a powerhead with a air venturi hose on it.

[johnnytrinh]

I had just change my gravel to LPS recently too and just did my first water change last week. Im also on water well. All fish were acting like they were suffering. Tank is a 210 with around 100 cichlids. Added more bubbles and pointed all power head up towards the surface. Fish were back to normal in a couple hours. But my water is really cloudy. Can't even see half was across the tank if looking on the side view

[moganman]

My fish look like they're gonna die on every water change I do. I've gotten used to it. They only stay that way for a few minutes. Nitrate and temp shock is what I blame.