I messed everything up now stuff's dying

[BF McUmber]

Short question: 
I had a nitrite spike due to killing too much bacteria in my 1 year old tank. If I was to just leave the light on at 100% and grow an algae farm, would that help me get nitrites under control quicker than just changing water and waiting? I have added new beneficial bacteria, it just has not taken hold yet.  

 

Long backstory: 
I am running on best guesses here. 
-I think I let nitrates get to 50ppm by overfeeding and an amano shrimp died, and then the other amano shrimp died. 
-Nitrates continued to be high as I assume the eco complete was holding onto it. I say like 6 cherry shrimp dying per day. I assumed due to the nitrates slowing coming down from 40. In addition my Black Beard algae was growing crazy. 
-We saw a fish with a shrimp in its mouth and thought, maybe the fish are big enough now and are killing the shrimp. Lets take them out and see if the death stops.  
-I caught the fish out of the tank, but had to move my castle and trim a bunch of plants. I gravel vac'ed to try to minimize the disturbance but still kicked up some stuff. In addition gravel vac'ing turned some of the good bacteria to the bottom of the tank. 
-I sprayed the BBA on the castle with peroxide while I had it out likely killing all the bacteria too. 
-I moved half of my cycled sponge to the new quarantine tank for the fish and left the other half in my HOB for the main 10gallon tank. I removed half the bio load I assumed half the sponge would do.  
-I have slowed the death of the cherry shrimp, but most likely because of the lower numbers. The more fun thing is that my Nitrites are like 0.75 ppm in the "big" (10 gallon) tank and like 1.0 in the quarantine bucket. This is despite not feeding and adding fritz zyme 7 (unopened but like 6 months old) and seachem stability that was 1 year old and opened. 
-I only have like 20 cherry shrimp left and am grabbing at straws as to what to do., So wondered if algae could help me. 
 

[AndEEss]

You need to do water changes. Stop adding BB. Get the nitrite down and keep it down. 
 

As you already have fish in the tank, you just need to do water changes every day until your cycle is back up.

And, stop making so many changes to your tank at once. 

 

Edited April 14, 2022 by AndEEss

[lefty o]

do like a 30% water once a day for a few days until you get the nitrates under control. dont go crazy and do huge water changes, as that can be detrimental too.