That shouldn't of done it....did u create low oxygen zones?
I use matrix almost exclusively on my display tank. Is pretty and functional. Does seem to help idk also have a ton of pothos....never had amonia spike from it. pH drop but it was slow and I keep South Americans and they didn't seem to care slowly brought it back up to tap level and added some crushed coral for buffering carbonates. Like two media bags of it. Added very slowly over the course of a month just a handful every few days.
Nice part is I can maintain 0 nitrate with out pH swing
Bad part is my ph is sitting at 6.8-6.9 and my chocolates stopped breeding. They were breeding every month when I was keeping it at 5.9-6.2...sorry going off topic
Another positive is I Can use snails to clean my matrix media again woohoo!
Sorry but two weeks of that shouldn't cause ur issue. Any other changes
Maybe a better explaination of your denigrate reactor?
Do U aerate ur display to off gas by products and get in oxygen? Do u have a DO test kit or TDSS? (Long shot I know)
What are your temps and pH?
Those are really the big question if you haven't cleaned a filter or did a massive substrate cleaning. What killed removed your nitrifying bacteria.
Now for the super duper bit question. Nitrite! Is it detectable
This will seriously **** your fishes gills and blood and oxygen.
So wish list here:
Amonia combined ppm or mg/l
Nitrite ppm or mg/l
Nitrate u can ignore this for now
pH gonna wanna do the low test (more then likely) what is your pH
Temp. Very important if you don't have the kits below
Now if you have them these can be handy with ur cercumstance
DO ppm?
Turbity or tdss total dissolved suspended solids?
And assuming a low pH what is your carbonate hardness
Understand if u don't wanna run these but can give u a solid perscription and fix with schedule if u want it