Posted: Wed Jan 28, 2015 10:38 pm Re: High Ammonia
The high ammonia was before the filter cleaning?
Those two filters would provide about 160 gallons of filter capacity for fish. That's less than ideal for a turtle in a 75 gallon aquarium, but I would think it could keep up. Is the turtle the only bioload?
Had you tested the ammonia level in the preceding 8 months?
High ammonia says you don't have the bacterial capacity for the bioload. Assuming this isn't the first time you tested ammonia and that the filters were keeping up, I'd have to assume something has changed. It may not be something you did. Perhaps the biomedia has become clogged, and there isn't as much surface area exposed to water flow.
Are you seeing rising nitrate levels, which show you do have bacteria? Do you have nitrites?
I've come to the point where I am a proponent of water changes during a cycle. The bacteria involved in the nitrogen cycle stick to surfaces. They aren't really free floating, so you aren't removing much. Yes, by pulling some of their food, the ammonia, you may extend the time for a complete cycle, but you're also removing poisons for your turtle/fish.
One final comment, by cleaning the filter/tubes with tap water, you did remove some nitrifying colonies. I rinsed out my Fluval 206 on a 20 gallon fish aquarium once. I didn't touch the hoses and I rinsed all media in aquarium water. That did create a mini-cycle that took a week and a half to recover.
Tobi a RES born in 2012
1 dog, 1 teenager, 3 aquariums filled with fish, snails, shrimp and a bit of algae