ATO Water Storage Size and Options

[chemaholic]

Well I finally got an Apex and I am planning to set it up to handle my ATO. What I really need to figure out is what size and type of container to use for holding the fresh water.

I have a 120 gallon tank. I go through around 7 gallons a week or so of fresh water. I am using a 5 gallon jug right now to gravity feed top off water to a float valve in my sump and it is a pain to refill and the lid leaks sometimes. I am going to be using a small submersible pump to move the water in my new setup.

It would be nice to only have to refill the container every 2-3 weeks. Does anyone have a suggestion for an economically priced water container about 25 to 30 gallons that I could put in the corner of the room that shares a wall with my tank?

Is 3 weeks too long for the water to sit in the tank? Will it start growing mildew or algae? I know if I use an opaque container that will cut down on some of that.

Has anyone ever tried hooking an RODI system directly to a float vale in their sump and just leaving the water hooked up to it? Basically anytime the float valve opens RODI water would immediately flow into the sump. No storage needed, no pump, no sensors. I am considering putting one in under my kitchen sink or on the outside wall adjacent to my tank and running some tubing to the sump.

 

[scuba steve]

You can connect an RODI directly to a flat valve in your sump, you just need to be aware of the potential downfalls for failure.
Say a snail blocks your drain, the water level in your sump will fall as the return pump fills the display but it's not draining back to the sump. Your float valve will open and fill the sump, since it has a limitless supply of water behind it, it will fill your system, the return pump keeps pumping out to the display tank, dropping the salinity and overflowing the tank until you get home and find the flood.
Additionally, small, frequent top-offs are hard on a RO unit, they do better filling a reservoir..
If you want to set it up directly you can do it using the Apex ATK and connecting it to your RO system with a solenoid instead of their PMUP pump and program it with several fail-safes for this configuration. This is how I have mine system setup.

 

[chemaholic]

You can connect an RODI directly to a flat valve in your sump, you just need to be aware of the potential downfalls for failure.
Say a snail blocks your drain, the water level in your sump will fall as the return pump fills the display but it's not draining back to the sump. Your float valve will open and fill the sump, since it has a limitless supply of water behind it, it will fill your system, the return pump keeps pumping out to the display tank, dropping the salinity and overflowing the tank until you get home and find the flood.
Additionally, small, frequent top-offs are hard on a RO unit, they do better filling a reservoir..
If you want to set it up directly you can do it using the Apex ATK and connecting it to your RO system with a solenoid instead of their PMUP pump and program it with several fail-safes for this configuration. This is how I have mine system setup.

Great points. That was the main one I had in mind. Your setup sounds like the right solution. I will just need to move my current float valve up a few inches.