TicketedBullet

*Update* added cuttle bone to the tank last night, checked parameters today and the KH is still reading 0. The apisto didn't make it, I checked his mouth and gills but didn't find anything out of the ordinary. All 3 adult guppies and 1 fry are all fine, if the issue was PH shouldn't they have been affected? I should also add the apisto was in my tank for roughly 3 weeks and arrived full grown, so age could have been a factor.

I should add that all other fish in the tank are fine. He was the unchallenged boss of the tank up to this point.

One male Cockatoo sitting near bottom of tank under cover. He is not eating, mouth is slightly open and gills moving rapidly. Colors still look fine. It's a 29 gallon heavily planted tank with aquasoil and sand substrate seperated by rocks and driftwood. Using an altered HOB filter with prefilter sponge. I tested the water when i noticed the Cockatoo not eating which is incredibly irregular, and the PH had dropped to 6(or below). I did a 50% water change and the current readings are below. I live in Florida so tap's PH is typically 7.5 and up. Tankmates are 3 GBRs, 3 Guppies, 3 banded Kulhi Loaches, 2 Ghost Shrimp, and an undeterminable number of snails. Temp: 79 PH: 6.8 KH: 0-40 GH: 300 Nitrite: 0 Nitrate: 0-20 Can't get a good picture/video as he won't come out from cover. I don't see anything in his mouth or any obvious injuries/ visible parasites.

I’m moving to southern Florida within the month and am quite interested in keeping some outdoor tanks and mini ponds. What has been your experience with outdoor fish keeping? If you were moving to Florida, what would you keep? Do you have any tips for an outdoor fish keeping noob?? thanks all!