Question
QUESTION: We have a 1700 gallon fish tank in the backyard with a 5,000 biofilter, UV, super water circulation system, and bubble pond water feature.  This winter we got 20 trout fingerlings and they were thriving until we had a heat wave and 7 of them died.  We put up a shade to cover the pond area, and the weather has cooled back down, and now the trout are about 10".  We are expecting another hot summer and wonder what we should/can do to keep the oxygen levels up in the pond.  I should also tell you that we flush the filter weekly when the weather warms.  This keeps the ammonia and nitrite levels down.  We also are using the barley straw (it fits nicely in the bubble pool that feeds into the tank).  

What else should we do for more oxygen?

Thanks for your help.

Melinda

ANSWER: Hey Melinda, it probably wasn't the oxygen that killed them it was probably the heat. There is not much you can do. I think you have done all you can do.If you have 13 trout that are 10" long I wouldn't be adding any fish. That is about the limit. When it gets that hot I don't turn on my pump because the water is still cool at the bottom and when the sun goes down and it gets cooler I will run my pump all night. Hopes this helps Eric

---------- FOLLOW-UP ----------

QUESTION: Do you recommend any type of testing kits for oxygen, nitrite, and ammonia?

Answer
Hey Melinda, any freshwater kit at the pet store will do. They all have the same chemicals in them. I have 2 salt water aquariums and I have tested the water maybe twice. Fish are pretty hardy as a rule they live in the wild alright. I just hate to see people spend more money on things like this. My pond is green it is 1400 gallons and I don't have a filter. I let nature take care of them like she does in the wild, plus I am looking for as low maintenance as possible.When the fish get bigger they use more oxygen. You may have to cut back to about 5 trout. Thanks Eric