Proper Dosing Line Height in Rear AIO Chamber?

[CayoHueso]

I'm setting up my dosing lines in the return chamber of the rear of my AIO. When I put the return pump in feeding mode, the water in the rear of the AIO reaches the dosing lines (which includes my ATO line). Is this an issue? Is there a chance for siphoning (either into or out of the tank)? When I turned feed mode off and the water level dropped in the return chamber I was worried that it may start a siphon and pull whatever excess RODI water was in the line. If it did, it didn't create a strong enough siphon to begin pulling from the ATO reservoir.

I'm using the Innovative Marine Custom Cradle Pro, I've got it as high as it will go. If the lines being in the water during feed mode and water changes is an issue, I will probably just lower the water level in the return chamber. Thanks!

 

[Formulator]

Your concerns are valid. I wouldn’t be too worried about siphon if you are using a peristaltic dosing pump (most common type). The design of a peristaltic pump inherently seals off the reservoir from the line outlet when at rest.

The issue is more about simple diffusion/osmosis of the water/ions in your dosing lines with the tank water. The liquid itself may not move, but when in contact with tank water all of the chemical ions (carbonate, calcium, etc) are free to move between the water in the line and the water in your tank. They will naturally move towards equilibrium, meaning if left long enough, the water in the tube and the water in your tank will be identical in chemistry. Essentially every time you feed, you would potentially be dosing your tank with the entire volume of dosing solution in the line downstream of the pump, but without actually moving any liquid from the line. On big systems with high demand maybe this isn’t a problem, but if the system is small and/or if the dosing line is long (higher volume), it could be an issue.

 

[Reefahholic]

I would just elevate it to where they’re not in the water. I personally never put mine in the water because I want to see it dripping when it doses. I wanna make sure it’s not clogging and functioning properly.

If you have to, and you can’t get the lid on, buy a plastic drillbit from tap Plastics and drill through your overflow box lid. Those bits will drill through plastic like butter.

Any pics of the set up?

 

[CayoHueso]

Solved it by taking apart the 1/4" push connects and flipping them upside down so the threaded/longer end was on top, and lowering the water level in the rear chamber slightly.