Auto Top Off via RO line?

Funkytone · #1 04-10-2008, 08:44 PM

I want to run my RO line over to the tank and design/buy (cheaply) some kind of an auto top off because I'm losing probably 1 - 2 gal a day and can't keep filling up the sump every day!

I've got the usual 1/4" line right now but from reading some recent posts on Gools thread about warming RO water, I think I'm going to go down to 3/8" and coil the line in the sump first.

What I'm mainly wondering about is what kind of auto top off systems are out there that are fairly inexpensive? or how about some good DIY's?

Thanks
-Tony

christyf5 · #2 04-10-2008, 09:35 PM

I was under the impression that RO units aren't supposed to be directly hooked up to the sump for auto top off as they aren't designed to be run for short times to produce small amounts of water. Also if it fails it could be catastrophic for your tank.

My auto top-off consists of a larger rubbermaid container (about 15 gallons or so) hooked up to a float valve in the sump. I fill the rubbermaid with topoff water weekly. This way if the float valve does fail I only have a few gallons added to my tank instead of an infinite amount if I'm not paying attention. If I am away from the tank longer than a week I have a large garbage can with a john guest fitting on the end that I can use in place of the rubbermaid (I don't use it permanently as its kind of unsightly in the room).

mark · #3 04-10-2008, 10:20 PM

I've got my ro/di connected directly to a humidifier float valve in my sump and been working trouble free for more than 2 years. Said before how many people have had or heard of someone having there furnace humidifier flood their basement. I haven't and I'm guessing there's a lot more furnace humidifiers out there than reef tanks.

Heard as well about having hooked like this causes premature membrane failure and TDS creep. I sent a e-mail the Aqua-safe about this and though the reply was a little cryptic got the impression it's not a problem. Having run mine like this, my TDS is usually low single digits and when they do rise, I'll change filters and resin and things settle back. Since this rise has only happen a couple of times in the 2 years since I've had the ro/di up, I'm contributing more toward dirty filters and exhausted resin than any thing else.

I'll be changing my membrane shortly but again figure this is more from having the unit doing 1-2g daily auto-tops and bi weekly water changes on a 200g system for more than 2 years than a directly connect float valve.

Again, just my personal observations.

Doo · #4 04-10-2008, 10:44 PM

I noticed this on Ebay...

There are 2 types - side mount & Top mount:

http://cgi.ebay.ca/WaterGeneral-Floa...742.m153.l1262

http://cgi.ebay.ca/WaterGeneral-Floa...742.m153.l1262

Not sure if this is what you are after

Delphinus · #5 04-10-2008, 10:50 PM

I run a float valve on my sump, the float valve is fed by a largish bucket reservoir (food grade 50gal drum). I manually fill the reservoir as needed, about every 2 weeks or so.

Previously I did have the RO/DI directly up to the float valve (ie., no reservoir). I went through 4 membranes in a year. You could tell they were shot because the TDS on the post-RO stage was >100. The constant on/off/on/off cycling every 5 minutes was (I'm convinced) the culprit. Since switching to a reservoir I'm on the same RO membrane now for 3 years and my TDS is still 0 on the post-RO stage.

YMMV I guess, but personally I recommend against just hooking up the RO/DI to the sump. A bucket is not hard to come up with, it's cheap, it's effective, and it protects your investment. KISS principle all the way.

Black Phantom · #6 04-11-2008, 12:13 AM

I've got the same thing as Mark. Just a float valve from my RO to my sump. Mines been running for over 5 years now with no problems.
Just make sure all your lines are secure and you should be ok
Oh ya, and I flush my membrane every week for about five minutes. Seems to work just fine

Funkytone · #7 04-13-2008, 05:14 PM

I think I'm going to go with just a bucket hooked up to a float valve to keep the costs down of changing membranes.

Are there any specific float valves that work better than others? also, Do you guys keep the bucket sitting higher than the sump so they're gravity fed?

Thanks

surgeonfish · #8 04-13-2008, 05:24 PM

I also think running the RO/DI too frequently is hard on the filters. I had to change my DI filter almost monthly! I now fill a 50 gal aquarium sitting above my sump weekly and use a Tunze Universal Osmolator Automatic Water Top-Off system. I know osmolator is $200, but one of my best purchases.

Delphinus · #9 04-13-2008, 10:42 PM

I just use a furnace humidifier float valve, costs around $10-12 at HomeDepot/Rona/etc. Just the black plastic one.

I keep my bucket on a stand that's just a tiny bit higher than the sump. Gravity does the rest.

Treebeard · #10 06-30-2008, 03:55 PM

Reviving an old thread....how do you plumb that set-up? Have any pictures?

Quote:

Originally Posted by Delphinus

I just use a furnace humidifier float valve, costs around $10-12 at HomeDepot/Rona/etc. Just the black plastic one.

I keep my bucket on a stand that's just a tiny bit higher than the sump. Gravity does the rest.