Questions about oxygen

[dandallasfan]

Okay so about a week ago I had a major problem using Algae Fix and ended up killing most of my fish. I have one surviving Demonsi left in my 90gal. tank. I purchased a oxygen test kit, but to be honest its really hard to understand. Does anyone know how to use these test kits?

[fischfan13]

Dan, I remember helping you out with this problem when it first started...sorry that it has ended up this bad.
Sounds like you have to empty the tank of water and refill it. The bacteria that is alive in your substrate will still live, but you need to do almost a 100% water change. You have to make this tank able to hold life once again. The algae fix has poisoned the tank and you have to rid the tank of these poisons.
What type of filtration are you using?
I would basically tell you to even scrap any of the media that is in your filters. Start up with some carbon in your filters. Use the carbon for about two days, throw it away and then do the same once again. Hopefully the carbon will get out even more poison.

Do you have any other tanks running?
If so, and this is really the last resort, I would think about emptying the 90g of everything...even the substrate. Let it dry out and then refill it and use either a filter from an established tank or the substrate from an established tank or both so that you can start up your 90g immediately.

[dandallasfan]

The weird thing is that I have a demasoni that has survived this...Crazy! He seems great. I have 2 Penguin 350 in the tank as well as a Power Head that has been on for over a week along with the usual bubble wand and air stones through out. I have done numerous water changes and wonder if the demansoni has survived do you think its ready for another fish? If so what fish would work well with one demasoni? I want to get about 14 more demasonis but I don't want to push it yet...

[fischfan13]

Dan, better to be cautious....no fish for a while.
Have you changed the media in the Penguins a few times?

As for Demasoni:
One or at least a dozen.

I have one Demasoni in a 55g with an assortment of fish and he stays to himself.