Oxygen issue? Or something else?

[sea-note]

Here is what happened - not sure what is relevant or which came first, but...

Had a heater malfunction and temperature rose to 88 degrees. Had an algae bloom. The 6 Ottos I have had for over a year died within 12 hours. All other fish in the tank survived (mostly Platys / swimmy fish, but the Ottos were the only algae eaters/bottom feeders).

I immediately tested the parameters and they could not be any more perfect. A water change and a few days without lights cured the algae bloom.

It has been suggested to me that the Ottos may have died due to lack of oxygen because the algae bloom. So, I assumed it was okay to re-introduce some algae eaters. They died pretty quickly and all of the Platys hover at the top of the tank like there is not enough oxygen.

I have a 60 gallon with two filters and have had the same setup for over two years. I have just reduced the amount of water in the tank in order to get more surface agitation.

I am looking for ANY help / ideas.

Thanks!

 

[HN1]

What type of filters?

Define "perfect" water parameters.

How did you acclimate the new arrivals?

What is your water change schedule / regimen?

 

[sea-note]

Sorry to be vague.

Ammonia: 0
Nitrites: 0
Nitrates: 10-12
PH: 6.5-7.0

I seriously doubt it was an acclimation issue as I have been adding fish to two tanks for a couple of years now (my tag line is way out of date). But they are floated for at least 15 minutes and then add small amounts of my tank water every 10-15 minutes.

My regimen is to perform water changes every 7-10 days (15-20%). Just before the algae bloom, I missed a water change and it was 16 days. I have a python, so the gravel is cleaned at each water change.

 

[dkpate]

The higher the temp, the less oxygen there is too.

 

[Blueiz]

There is a possibility that the algae eaters that you added were from bad stock and it has nothing to do with your tank..