Odd residue from ATO

cymonous · Dec 12, 2019

I recently transition from a 100g to a 40B. I had both running while the 40B was cycling. I planned on moving equipment from the 100g to the 40B when it was done cycline. That included just about everything for the ATO. The ATO has been in use for the 40B for about 3-4 weeks now. I noticed today the residue in my sump directly under the outlet of the ATO. The PVC overhang and the tubing are all new. The ATO container is a clear rubbermaid container and it is not dirty at all. Has anyone else experienced this? Do you know what it could be from? Anything I need to do?

reef lover · Dec 12, 2019

Very strange...do you have di cartridge on your ro? Do you know the tds readings?
Do you have a refugium light that runs near it?
Also mentioned a clear holding cont. Does it get hit by sunlight?

cymonous · Dec 13, 2019

I have a DI on my RO. It still has about 75% usage left and my TDS is 0 output.
I am not running a fuge on this sump, so no refugium light. The container is in my basement, one small window about 7 feet away. That side of the house faces Northwest. So, I don't believe it gets any direct sunlight. A couple days ago, I put insulation over that window though(thin windows).

Super Fly · Dec 13, 2019

looks like algae to me, is the ATO pipe aimed at the area of question? if so, perhaps the water running on glass is causing this?

cymonous · Dec 13, 2019

Super Fly said:
looks like algae to me, is the ATO pipe aimed at the area of question? if so, perhaps the water running on glass is causing this?

Yes, the ATO pipe is aimed at the area of question. So, even though the ATO fill water is 0 TDS, it would create algae on the glass?

Super Fly · Dec 13, 2019

cymonous said:
Yes, the ATO pipe is aimed at the area of question. So, even though the ATO fill water is 0 TDS, it would create algae on the glass?

I don't believe o TDS completely prevents algae in the tank, just helps minimize. One way to test this theory is try aiming the pipe away from glass and see what happens?

cymonous · Dec 13, 2019

Super Fly said:
I don't believe o TDS completely prevents algae in the tank, just helps minimize. One way to test this theory is try aiming the pipe away from glass and see what happens?

I'm sure doing this would stop the residue from forming more, but I'm curious on what my source water could be adding to my tank. What if I attached some filter floss to the end of the ATO pipe to see if it catches anything? I can try to find a way to have the ATO water not spray on the glass.

Super Fly · Dec 13, 2019

Not sure if that'll reveal anything though as ATO is clean RODI water... I believe there's probably some light source in the basement causing this. Is the area around sump completely dark with lights off, perhaps the NW window was letting in afternoon light?

cymonous · Dec 13, 2019

The area around the sump is not completely dark, but there is no way direct sunlight can hit the sump. The NW window is in the basement with the ATO. I did not think about this at first, but the ATO tubing is clear and is right next to the basement window. Since I covered that window, hopefully the residue will stop forming.