What happened

[straick]

Went out to dinner and just got home, only to find the neon tetras all dead, top of the tank covered in foam(run a small air pump at night to keep CO2 from going too high at night), and no one else acting normal. The only way I can think of to describe the foam is like the foam you get in your sink when you do dishes.
Did a BIG PWC(almost 90%), and everyone seems more or less normal now, but I'll have to keep an eye on things.
The tank is a 10 gallon, 2 crypt wendtii, 2 sprigs of anachris, Aquaclear 20 hob. Had 5 Neon tetras(all bodies have been found sadly), a betta, 4 amano shrimp, and 1 otto. The ammonia, nitrites, and nitrates where all 0 in the water coming out(lots of fuzzy algae at the moment). PH was between 6.8 and 7.0.
What could have caused this to happen?

 

[Hubert90]

Did u test ur water parameters before u did ur pwc?

 

[jetajockey]

can't think of any reason why the tank would foam up like that unless something made its way in there.

 

[straick]

Those number were the before PWC numbers. Good news is, I have lost anyone else.

 

[43Gallons]

That is really strange... Can you think of think of any recent additions to the tank, cleaning jobs you did, chemicals you added etc.? Sorry for the basic questions.

 

[mfdrookie516]

are you running diy co2? IF so, what's your co2 concentration usually run? Any chance some of the mix made it in to the tank?

 

[Randi]

Really sounds like soap got into the tank. Maybe you put your hands in the water after doing some cleaning?

 

[43Gallons]

Or, not to sow any dissent, one of your household members may have incorrectly cleaned the tank, added chemicaks incorrectly, or mishandled a water change. Maybe you should ask, just in case.

 

[straick]

Think I might have an idea of what happened. My landlord is OCD about using insecticide to keep sugar outs out(they don't hurt anything anyways). Found out that he went overboard while spraying, right outside the window that's above the tank. I've already asked him to stop for my health, but he keeps on doing it. Think I'll introduce him to some much more natural solutions.

As far as the cleaning stuff getting into the tank, I'm obsessive on not doing ANYTHING with the tank if I can avoid it after I've been cleaning(which I wasn't yesterday.
The DIY CO2 would have to fill a 2 liter puke jug(that what I call it), and then make it through a home done bubble counter before it could get into the tank. Can't say what the CO2 levels are right now with any precision(town uses a phosphate based water softener), but everytime I've checked it by KH/PH charts, it's been very high(over 100 ppm), but no one seems to even notice it.
The only thing I've added recently was a phosgaurd pillow to deal with the phosphates, including the ones that are in my tap water.
As of right now, Barry(betta) seems fine, 3 of the 4 ammano shrimp are out cleaning their wendtii(yes, they only seem to clean the one, and ignore the other), while the 4th one has turned a blueish color and is spassing out, and the one otto seems very lethargic right now. I'll have to keep an eye on those two to see what happens.

I'm still hoping to figure out what happened, but may never know for sure.