Ditto to the above.
Ideally the water in your filter should run through course filter media (ceramic tubes or bio balls), then course sponge, then fine sponge and finally a layer of floss. The course media is only rinsed in a bucket of tank water, the sponged squeezed out in same bucket until free of grunge (but not too clean) and the floss replaced if clogged.
The floss in my filter is probably only one tenth of the canister volume. Cleaning the filter in this way retains the bacteria integrity, avoids mini-cycles and, as you have experienced, bacterial blooms.
Hope that's of some help.
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