Neglected tank

[nwsharksfan]

At the risk of having someone call fish services on me, I have a confession to make. I have a 92 gallon tank with a tiger Oscar and a Chocolate Cichlid in it (I know this is pushing the stocking limits already). Anyway, I moved the tank into the garage so we could install hardwood floors. Out of sight, out of mind. I haven't been keeping up on maintenance all that well. I noticed about 4 days ago that my Oscar was starting to float around vertically. I didn't test the water but did a 40% water change. During the water change I stired up the black sand substrate quite a bit and there was no lack of brown cloud. Today I tested the ammonia level and it was 4 ppm. This is the first time this tank has registered any ammonia since it was first cycled 7 years ago. The nitrate level was 40 ppm. I cleaned out both canister filters and did another 40% water change today. It should also be noted that due to an electrical issue the filters have been off for about a day and a half. Well, now the electrical issue is fixed and the filters are cleaned and working. Aside from continuing water changes every couple days, is there anything else I can do to bring this tank back in line? Should I use something like ammolock... or would this prevent the re-establishment of the bio filter? I don't use carbon because I am convinced this leads to HIHD for Oscars. I put a little aquarium salt in there just because.

[OneTwoRedBlue]

According to the API website:

AMMO-LOCK locks up ammonia in a non-toxic form until it can be broken down by the tank's natural biological filter.

So it's not going to deny the bio filter of food. For the sake of your fish I would use it, 4ppm is a lot. Be aware that the ammo lock neutralized ammonia will still read on test kits.

[nwsharksfan]

So, I've done 50-60% water changes every day for the last 4 days and the ammonia level is down to somewhere between 0 and .25 (very slight green tinge, but not all the way to the .25 color). Nitrites are 0. Nitrates 10 ppm (didn't test initially. Would hate to see what it was). Ph is 6.8. I didn't add ammolock. I normally use prime to condition my tap water and it says it neutralizes ammonia so I've just been using slightly more of it than I usually do.

I don't use any additives in my fw tank. I was wondering if there is any benefit to using cycle or stress zyme to try to kick start the bio filter again ... or if these products are just snake oil.

I also noted the temp in the tank is 82 degrees so I turned it down a bit.

[OceanDragon1]

I wouldnt advise ammolock personally as it can often end up creating more nitrite then you end up with nitrite poisoning in your fish which isnt very fun at all
I had a similar situation after taking in a rather badly neglected tank, fixed it within a week with about a 30-40% water change daily and throwing in a bottle of bacteria starting kit (i think it was safestart by tetra) just to re establish some bacteria and put everything back in balance

so if i were you id grab a bottle (youll only need a half dose or less) and chuck that in