White bubbles/foam on the tank's edge. What is it?

[lix.ma14]

i'm very puzzled at the white bubbles that form on the edges of my tank's water surface. If I look closely, it looks like tiny bubbles on the tank edge. Looks almost like saliva. i don't know what it is. The tank water is very clear. i do 50% WC every week. I changed the filter floss just last week to try to stop the foaming. That didn't help. i've had this probelm before but it ended after I changed the filter floss. I did that this time but the bubbles still formed.

the bubbles don't have any color. Just clear or white depending on bubble density. Water doesn't smell foul. Fish fine.

This issue started after I added my Fly river turle in the tank. not sure if it's from the increase of bioload. the tank only has one armatus and the FRT.

I'm worrying that the foam is some kind of bacteria or the imbalance of ammonia etc. how can i stop this?

Any info would be great. thanks.

 

[duanes]

Foam forms at the air water interface, especially near where there is water movement and where proteins are present. It is usually composed of dissolved organic carbon/proteins. The more agitation at the waters surface, the more foam forms. It can easily be seen in billows of foam at the bottom of waterfalls in nature, or after heavy wave action.
This is why foam fractionators work, protein skimming as a form of filtration. The turtle may have put the tank a bit over its normal equilibrium, and as far as maintenance goes, require you to either, do more frequent water changes, or rinse the filter floss more often, or both.
A foam fractionator below.

click on the video to start

 

[lix.ma14]

Foam forms at the air water interface, especially near where there is water movement and where proteins are present. It is usually composed of dissolved organic carbon/proteins. The more agitation at the waters surface, the more foam forms. It can easily be seen in billows of foam at the bottom of waterfalls in nature, or after heavy wave action.
This is why foam fractionators work, protein skimming as a form of filtration. The turtle may have put the tank a bit over its normal equilibrium, and as far as maintenance goes, require you to either, do more frequent water changes, or rinse the filter floss more often, or both.
A foam fractionator below.

click on the video to start

just got new filter floss and i'm planning to do a WC today. i guess the increased bioload contributes to the dissolved organic matter.