I cleaned the tank out switched the filter did a 60% water change
I have tested my water and it’s not the best but nothing super crazy either.
your test should be 0 ammonia and 0 nitrites. Nitrate should be as close to zero you can achieve and no more than 40ppm.
I have a 6" 125G with only 2 10in fish and they get 3 80% WC a week.
A 50% water change every other day with those fish in such a tiny tank( to keep them healthy), would not be overkill.
Hello; After the onslaught you, the OP, have gone dark in this thread. I am guessing you hoped for some suggestions other than what were received. Here is my current take. That you cleaned the up the tank and changed out the filter, then did a 60% water change (WC) suggests a misunderstanding of the function of a filter and the nature of the beneficial bacteria (bb).
Since the OP may have checked out due to what he may have felt has been harsh treatment from us the following might be a primer for other less experienced fish keepers. First thing we judgmental old hands might educate about might be filters. I start with an understanding much will be left out as i do not wish to write a book.
The main purpose of a filter system is the mechanical filtration (polishing) of the water. Many if not most also like to add that filters are home sites for bb colonies. The bb can and do live on the surfaces of a filter. A thing is the bb also can and do live on surfaces everywhere in a tank. Witness that many of us have run cycled tanks using only simple bubbler operated sponge filters. The bb form colonies just fine.
Now one of my speculative takes is the bb may be more concentrated on surfaces which have moving water on or near them. This notion would make a power filter a prime area for bb colonies. The surfaces would include the tubes and boxlike container walls as well as the dedicated materials we stick into power filters for the exact purpose of being homes for the bb. Ceramic "bio" balls, plastic "bio" grids and such. I even used glass marbles in a large HOB back in the 1970's which worked well.
Here is one of my contrarian ideas. I try to have layers of media in a filter. The first layer is some sort of floss or material intended to be a mechanical filter to catch and hold detritus of the tank. Also filter material which I intend to and do throw away from time to time. My thinking being that detritus is often rotting organics and fish poo. Stuff i want removed from my tanks. Some on here are dedicated to the practice of reusing such material rather than throwing it away and replacing with new. I follow the reasoning but contend there is greater value in disposal over reuse.
The idea is there are bb living in that first layer of filter floss and throwing the floss away is also discarding the bb. I do agree some small percentage of bb may be in that material. My reasoning being the greater percentage of bb colonies will be elsewhere in the tank. That the small percentage lost is not critical as long as not too much is tossed at one time. One of my favored filters in a HOB with two filter chambers. I have initial layers of throw away floss with some sort of more "bio" friendly material behind. When i toss the dirty first layer I do not clean that secondary bio layer. I also only toss the floss from one side of the HOB at one time. I wait a couple of weeks before tossing the floss from the other side.
Back to the OP's issue. I gather he changed out filter material when his fish began to be damaged. likely was the wrong move since the speculation seem to be the fish were suffering from ammonia burns. With ammonia in a tank (which appears supported by the OP's mention that the water tested out "not the best") the filters should have been left alone. Only the WC was helpful.
Let me leave with a homework assignment for someone. There is a notion floating around which goes something like the more power filter we have then the more or bigger fish we can keep? true or not?
