Auto Top Off

Yes you will need the auto shut off or your ro unit will keep producing waste water. I assume the float valve you're talking about is hooked up to the holding tank, only stopping the "good water." Along with the float valve and auto shut off valve, you will need to get a one-way check valve if you don't already have one. Here are some links to what I use for my auto shut off. If you use something completely different, ignore this, but it's worth a look.
Float Valve
Auto Shut Off Valve
One-Way Check Valve

 

I can try taking a picture of how it's setup if you're unsure how it works.

 

The Level Loc ATO system is designed to be attached to your RO unit. It has a backup float switch and a solenoid to shut off the RO water in case of over-filling. You may want to check into that. It's a little pricey, but it looks like a high quality setup and I've heard good reviews.

Now, that being said, it's design does not make it an appropriate ATO in a couple of cases.

1) You plan to dose kalk with your top off water
2) You plan to have your top off water at a lower level thank your sump water level.

Both of these limitations are due to the fact that it's designed to be direct attached to the RO unit. Due to the incorporation of a solenoid, you can't add kalk to your water. For those using this ATO, that's typically not an issue since it's attached to the RO unit and there's no way to add kalk in the RO unit. Second, the Level Loc relies on gravity or pressure to push the water. An RO unit have the water under pressure so this should not be an issue. It's not like other ATOs where a switch box powers a circuit which turns on and off a pump. The Level Loc uses no pump. All gravity/pressure fed.

The general recommendation is not to direct attach your ATO to your RO unit because float valves will fail. It's not an if, it's a when. For example, if your RO is direct attached to a float valve in your sump and that float valve fails, you start dumping 2 to 3 gallons of RO/DI water into your tank per hour...eventually flooding the sump, reducing the salinity of the water and you can imagine what happens from there. I know Troy uses a 5 gallon bucket as a holding tank and adds kalk to the water while it's in the 5 gallon bucket. There's one float valve to keep the RO bucket full and one in the sump controlling RO water to the sump.

Anyway, give your ATO system a bit of thought on how you want it to work, then check out www.auto-topoff.com for some good options. Also, if you're interested in the Level Loc, Bulk Reef Supply has them cheaper than anywhere else I've seen.

I hope this info was helpful.

--AJ

 

I just did mine a few months ago. What I did is have a the hose coming from the RO unit to a bucket w/ a float valve. The bucket is where I add the kalk at, but if you don't use kalk then you don't haft to. From the bucket I have a hose going to my sump w/ another float valve. It is all gravity feed, and requires no electricity. There is no real fail-safes with this, so I do have to keep a eye on it daily, but that only takes a few seconds. I also only keep about 2 1/2 gallons in the bucket, and with tanks over 200g, that much RO water all at once isn't going to hurt anything.
I do have some pics of mine if your interested in something like that. Just let me know.
Troy

 

Hi Tony, This will help you with your R/O. I had to hook mine up a little bit different then the manufacture suggested but it worked all the same.
 http://www.airwaterice.com/product/...valve.html,  these guys are club sponsors, and good to work with!
I think there maybe a discount for club members but I cant remember for sure?

 

Tony here are some pics to help out.
The red line is the waste line from the membrane, the other line goes to my DI.


This is my RO/DI storage tank. It has a modded float valve on the lid with a safety over flow line in case a valve were to stick open.

This is the dual 12volt solenoid valves used for auto top off of main tank and RO/DI tank.

Hope this helps. Good luck!