please help!! help advice on fish and meds

[uwmaniac]

55 gal planted
diy co2
new cannister filter with whisper 60 and power head going
ph 6.6 -7 past 2 days
nitrate 70 (tons of water changes cant get it down)
nitrite-0
ammonia-0


i just bought a dojo loach and a new plant (anubias i think) and had them in my planted 10 gal for a few days then put into 55 gal, two days later my girlfriend noticed fin rot on male guppy (older) and decided to med both tanks since i was out of town for a few days. i think she used minocycline white tums sized tablet with a M on it and line under the M. LFS said one tablet per 10 gal. three days into meds (doing water changes before dosing 25% about) have now lost betta, rasbora, no neons lost (have 15 ) honey gold guarami and now my dojo is messed up, in just a couple of hours hes gone down hill, he has small red dots on him, looks like somthing small growing on his head and his eyes are cloudy moved him out of tank with fresh water thought it might be meds heard something about scaleless fish being affected. could someone or everyone please PLEASE help, i dont want to loose anymore fish and i really dont want my dojo to go

[Quixotic]

The ntirate reading doesn't change after water changes? Then I suspect that either your nitrate test kit is faulty, or there is nitrate from wherever your new water comes from.

While your medication don't seem familiar in these parts of the world, you could have transferred the sick individual to a hospital tank if possible, and medicate the hospital tank itself. The isolation would ensure that healthy fishes are not affected by medication. Some fishes are rather sensitive to medication and that include scaleless fishes.

Also, when using medication, always provide additional aeration. Medications will generally bind oxygen. When dissolved oxygen gets too low in the tank, then the fishes may suffer from hypoxia. I suspect that this is the cause of your fishes deaths.

I would suggest for now that you perform a large water change to the main tank and monitor the situation from there. If your guppy is still showing symptoms of rot, isolate to a hospital tank and continue with the same medication.

As for your dojo loach, isolate it to another hospital tank. Cloudy eyes are generally caused by bacterial infections, so ensure that you are always on top of water conditions. You may choose to dose some general anti-bacterial medication (Melafix/Pimafix), but in smaller dosages because of its sensitivity.