Backyard Aquaponics
A place to discuss aquaponics

My fish were feeding just fine all year and now they will eat sinking pellets but will not come to the top and eat the floating pellets anymore.

I have a 300gal Rubbermade tub and a 300Watt heater.

The only difference lately is that the whether is now colder. I have a heater in the tank but I ordered a larger heater that is more for the size tank I have. The temperature of the water reads 78F. The heater I ordered is 1000Watt and for 300-600 gallon tanks. I hope the only issue is the temperature. I will see when the heater arrives.

What kind of fish? And are your water readings normal?

Tilapia and the PH and Ammonia are fine last time I checked a few days ago but I am going to check again shortly.

Three of my four tilapia tanks the fish won't feed if I am watching. But the feed is always gone if I walk away and look from far off. My big tank they will come up and eat.

It's weird that you mention that because I have noticed that I will hear some snapping and popping on the water surface if I walk away. However, some of the food is still floating when I return later but most is gone.

It's just weird because they used to eat from the top ferociously at every feeding while I stood there.

Could you have an animal that is spooking the fish?

Maybe a cat at night time is scaring them from the surface?

My setup is in my garage. No animals.

It looks like now my ammonia level IS high. I do not want to change the water out as it will drop the temperature dramatically.

How do I lower the ammonia. I read where people have done water changes or added egg shells. Can I use something like Zeolite Ammonia Remover Pouch and have the water flow over the pouch when going into my grow beds or just leave the pouch in the tank?

Just do a little water change at a time. I have done 60% water changes with my tilapia and they did just fine. Well water is 67F and my tanks usually run about 85F.

OK, will do, thanks for the advice.

Have you added salt to your fish tank?

No I have not ever added salt.

My new heater came today and the temp is already up to 83F. I added more water as my 300 gal tank had about 10inches of room at the top. Added about 25 gallons. As soon as I get some time, I will run the pump and let the water flow outside then refill the tank back up using my garden hose with the PH/Chlorine filter on it.

The fish already seem more active. Before I walked over to the tank I could here them snapping at the top of the water.

If you are not running constant flood now, it might help to do so for a few days till your water stabilises.

I drained a little over half the tank and then filled with clean filtered water, then tested again and the ammonia is still high. The fish are still active however, they are not really eating the pellets but if I throw in a leaf of bok chow or lettuce from the grow bed, they nip at it pretty good until it is gone.

I purchased some ammonia filters from Amazon yesterday with a rush 1 day ship and they will be here today. I will place the pouches in the plant beds under the incoming water spout and let the water flow constantly for a day then re-check ammonia levels.

Stop feeding them for now. Every time you feed them, you are adding ammonia to the system. Your nitrification bacterial colony might have been compromised. Keep an eye on your water parameters, and pretend that you are cycling your system. When the ammonia stabilizes WITHOUT the added ammonia absorbers, then continue feeding. I would be redisent about usung the ammonia absorbers because they could be adding something else to your system that you might not want in it. Plus, you need to let the nitrification process happen naturally, that way it can adapt to the ammonia levels that your fish put out.