Water Change issue?

[mikey5290]

Water change day-every Saturday
-use a hose connected to kitchen sink, then to dyi pvc with ball valve to control flow. Always use prime with every water change.


I always do my 75g mbuna , 40g Angel, and 20g community tank this way and no issues so far. (all 40% pwc unless otherwise needed).

My mbuna fry tank (20g) gets pwc of 25% every second day and is usually done with buckets as it is just faster.

Problem!!!- today I used the hose to fill the fry tank and half hour later I have 5 dead fry. I have yellow labs, rusties, and had afra cobues in this tank but all the dead were afra cobue. None of the others seem affected.

My Angels seems to be hanging around the top of the tank more than normal but no real issues so far. (only been about an hour).

Any ideas what could have happened? Did I cause this?

I use a piece of course sponge in the pvc pipe to avoid sucking up fish while siphoning as well as to break up some of the micro bubbles when filling, could those micro bubble be the culprit?

Not a good day

 

[mikey5290]

Well it's been 7 or 8hrs and no further deaths, angels still not acting quite normal so keeping my fingers crossed. I added another air pump and stone as well as removed the aquarium lid ( the only thing I could think of to try). Remaining mbuna fry seem ok, and are eating.

Question- Has anyone else had issues with water "off gassing" during water changes?

I read numerous things online about this and it's affects on fish and the reasons for letting your water age for hours or overnight.
However with the popularity of "python" and Aqueon" water change systems I would think more people would have issues.

Thinking I might be going to back to the buckets

 

[ESeck]

Did you test your water parameters? I'd be curious if there was something spiking in your water.

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[MissGurnus]

Yeah I second that. Sometimes stirring things up can release thing buried in the substrate

 

[Brookster123]

When I was raising fry I kept a 5 gal bucket with heater and aeration. Fry are extremely sensitive to swings in parameters and temp. Your tap water usually swings in ph over 24 hrs. Mine comes out around 8.2 and drops to 7.4.. even a 5 degree temp swing could take out the weaker ones. Look at it like a quick cull and don't let it happen again

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[mikey5290]

Did you test your water parameters? I'd be curious if there was something spiking in your water.

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I did test the Angel tank and I do believe you are correct. Nitrite and Nitrate present after water change (.25&5-10ppm) , haven't seen any Nitrite in a long time tank is fully cycled. Changed more water out (used buckets this time) and they are acting better this morning.

"0"'s across the board on the fry tank. As I said I do water changes every 2nd day and I vaccuum on the other days with a power head and filter floss. It a bare bottom tank.

 

[mikey5290]

When I was raising fry I kept a 5 gal bucket with heater and aeration. Fry are extremely sensitive to swings in parameters and temp. Your tap water usually swings in ph over 24 hrs. Mine comes out around 8.2 and drops to 7.4.. even a 5 degree temp swing could take out the weaker ones. Look at it like a quick cull and don't let it happen again

Sent from my SAMSUNG-SM-G900A using Aquarium Advice mobile app

I try my best to match temps within a degree or 2 max (using digital probe checking output often).
PH? Didn't think of that as a possible cause. I will have to test out of the tap vs 24 hrs later.