hi friends, please read this entire post before commenting to have the context.

i work in a pet store and largely oversee the fish department. we have a plant tank that also contains two goldfish (roughly 300l with a sump). on my days off, the manager decided to put in wunder tonic to said tank as one of the fish’s fins were looking frayed (rather then… take him out and put him into one of the nine quarantine tanks we have…).

everything is now blueish green. the glass, the ceramic noodles, the filter wool, all of the plants (that are for sale for customers to buy) are now blue. half the plants are begun to rot and die (i’ve easily written off fifty bucks so far in dead plants) but that is whatever to me. i cleaned the sump the best i could to hopefully salvage anything that wasn’t already tonic-ed but it’s in EVERYTHING. i changed about 150l of the water out and it’s still incredibly blue.

so i’m here to say… what the fuck do i do now? is it worth taking ceramic noodles/filter mesh from the other tanks and putting it in there in hope to jump start the bacteria cycle or should i just let it run it’s course? any advice would be greatly appreciated.

results were gained with api freshwater test kit (the drops) ph: 7.6, amm: 0, nitrite: 0, nitrate: 0. it usually has nitrates around 10-15, and a ph of 7.2-7.4 (same testing method, done weekly).

i cannot take photos as this is at my work and i don’t want to risk being identified. me and the previous fish girl having been lovingly caring for the fish and the fish tanks here for years now. while we are a pet chain store (not petsmart) and it makes me want to cry to see the plants rotting. any help would be greatly appreciated as to where to go or how to salvage this.

and for anyone wondering… the goldfish is completely fine.