Mission Impossible...DIY ATO

[phenom5]

I need a DIY auto topoff. Seems easy enough, but here's the problem. I have no room for a water container to hold RO/DI water for topping off. No room in the stand, and putting beside the tank is not an option...no room for that either really. My RO unit is currently hooked up to the sink in one of the bathrooms, which is a fair distance away from the tank.

The only real option, as I see it is to hook up the RO unit to my hot water heater, which is located directly behind the tank. Good idea? In theory, it seems like it would work. There's a cold water going into the hot water heater, and there's a drain for the waste water. I'm just not sure if this would be a problem or not.

I dug this thread up DIY ATO with Solenoid. Any thoughts? I think I would probably want to put the solenoid before the RO unit, but how would I bypass the float switch to make water for water changes? Any problems with the water that would sit in the unit when it wasn't running?

Any other thoughts on an ATO for this setup?

[One Dumm Hikk]

I don't have a lot of faith in making things more complicated than you possibly can. The more that can go wrong, potentially will go wrong.

Moving the RO/DI to the water heater area is a good idea since you have cold water and a drain. Would make it closer.

Since the hot water heater is directly behind the tank, what about an ATO tank in the hot water area and plumb it through the wall, have it gravity fed into the sump. End of problem

[phenom5]

No room for a FW topoff tank. After looking at it more, I'm not sure that there's room for the RO unit. And I'm not crazy about hooking it into the hot water heater either.

Another option is to hook the unit into the waterline for the washer. How far can you move the water coming out of an RO unit? A straight shot from the washer/ dryer to the tank is about 14'. Running the line up, and through some duct work to get it to the tank is about 18-19 feet.

[phenom5]

Bump.

Still looking for an answer to...

How far can you move the water coming out of an RO unit? A straight shot from the washer/ dryer to the tank is about 14'. Running the line up, and through some duct work to get it to the tank is about 18-19 feet.

I suppose I could just go buy 20ft of 1/4" ID tube and see if it'll work...

[coralfragger101]

Yes - It will work. Mine goes from the washer/dryer area up through the ceiling, across a hallway and down into my fish room.

[eznet2u]

Just a pet peeve...

It's a "Water Heater", not a "Hot Water Heater". It heats COLD water, not hot water.
A "Hot Water Heater" would be a steam generator.

We now return you to your thread.

[coralfragger101]

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[stugray]

It's hard to believe that you have a space that holds a water heater, but not enough room for a RO/DI filter & a resivoir.

How about an UPGRADE to a tankless water heater ..... it is more cost efficient and takes up less space ....wink wink, nudge nudge....;-)

The best answer is to find a way to put the filter in with the WH. Mine takes up about 2 cubic feet. Then route that to a resivoir ( what is directly above the water heater closet? ...attic, closet above? )

Then feed that via gravity back to the tank/sump.

Stu

[phenom5]

Originally posted by eznet2u
Just a pet peeve...

It's a "Water Heater", not a "Hot Water Heater". It heats COLD water, not hot water.
A "Hot Water Heater" would be a steam generator.

We now return you to your thread.

Oh sure...go ahead and get all technical. If I have to start worrying about using the "correct" term for things, I'm really going to have to rethink this whole Interweb thing.

Originally posted by stugray
It's hard to believe that you have a space that holds a water heater, but not enough room for a RO/DI filter & a resivoir.

How about an UPGRADE to a tankless water heater ..... it is more cost efficient and takes up less space ....wink wink, nudge nudge....;-)

The best answer is to find a way to put the filter in with the WH. Mine takes up about 2 cubic feet. Then route that to a resivoir ( what is directly above the water heater closet? ...attic, closet above? )

Then feed that via gravity back to the tank/sump.

Stu

I could probably squeeze the unit into the water heater closet, but it'd be tight. As far as what above it...the roof. Flat roof, ranch-style house in the desert.

[phenom5]

Originally posted by coralfragger101
Yes - It will work. Mine goes from the washer/dryer area up through the ceiling, across a hallway and down into my fish room.

Thanks. I think I'm going to give it a go. I'll give it a test run first before I go drilling any holes in the walls. I think this is the kind of project that's best done when the wife's at work...I'll let her come home and discover this wonderful little addition on her own.

[hahnmeister]

I designed this and posted it over at nano-reef.com for the nano-peeps:
http://www.nano-reef.com/forums/inde...howtopic=29093

[coralfragger101]

Hmm - that link just takes you to the main forums page.

[hahnmeister]

http://www.nano-reef.com/forums/inde...howtopic=29093

[hahnmeister]

hmmm... RC is blocking it. Its over at nano reef dot com, thread number 29093.

[ReefingBuddha]

I have a 300GPD RO/DI unit hooked up straight to my tank without a tank in between. I use 2 float switch, one on a solenoid, which is normally closed, and another that controls the power to the solenoid and booster pump, so there is a backup in case one gets stuck. I have never had a problem (going on 8 months now) and you could put in another solenoid or two in line to get even more peace of mind.

Its worked for me.

[hahnmeister]

If you still cant find the ATO I linked to above, let me know. Its about $7 for the pump, $??? few for the float switch, and the rest should be scraps you have laying around like a 1 gallon jug. If you want, you can run it on the two batteries that the ATO comes with... they will last you a good year usually. Or, you can splice in an AC/DC adapter that does 2.5-3v (many old cell-phone chargers that you may be throwing out anyways). All you do is splice the float valve into the wiring inside the battery powered air pump, so when the valve goes down, the air pump turns on. When the air pump turns on, you have it feed into a sealed container of about 1 gallon which you keep your RO water in. As the container fills with air, the water outlet (at the bottom) then forces water out and into the tank. Simple, and good for tanks up to about 20g. The water can run vertical about 3-4' before you start having problems with pressure on the air pump, but usually, the jug just sits next to your sump. If you can find an even larger container for RO water, you can use it instead for the ATO as well... as long as you can seal it. A 5g water jug from the grocery store is one possible alternative.

No AC, no float valves to fry, no relays to fail. Should the ATO get stuck for some reason, the god news is that it will only fill as much as in your ATO in the first place... so if its only 1-2 gallons, this is no big deal usually... just sump space.

[eznet2u]

Originally posted by thirschmann
I have a 300GPD RO/DI unit hooked up straight to my tank without a tank in between. I use 2 float switch, one on a solenoid, which is normally closed, and another that controls the power to the solenoid and booster pump, so there is a backup in case one gets stuck. I have never had a problem (going on 8 months now) and you could put in another solenoid or two in line to get even more peace of mind.

Its worked for me.

You are shortening the life of your membranes this way. Google "TDS Creep".
An RODI unit needs to run for a while to clean itself off. You are also not getting the purest water that you can get out of it. Hook up a TDS meter and you will notice that the first gallon or so is not "0 TDS". It will run about 3-5 on the meter. I run mine into a 35g barrel and store it there until it is needed. I have a separate barrel for top off. (15g)

[ReefingBuddha]

I know what you mean eznet2u but as I have a large sump my ATO only comes on every 2 days and when it does it do so for about 15 minutes, the first 15 to 25 seconds of which have a slightly higher TDS before it drops down. Not something I'm all that concerned about. Further more I have a automatic flush solenoid on a timer for my membrane as well to help keep my startup TDS as low as possible.

I think that should do the trick, please let me know if I've left anything out.

[areze]

does sound like that would handle the issue. of course your situation is not the norm

having an unlimited supply of fresh water hooked to the tank is always a concern, redundancy should be mandatory in any and all levels that could potentially fail, double float switches, double solenoids, ect. when you get to that point, on some tanks the cost might be prohibitive which is what I think scares most people off from doing it, or they just go with a single setup, if it fails, its curtains for the tank and the floor. granted, if a resevior setup fails, your still looking at a chunk of water and possible death, but atleast you know just how much water is possible... and its less then "unlimited"

anyway, if you do it, do it right, double everything, redundancy is key so you can sleep sound and go on a 7 day vacation without cold sweats.

[phenom5]

hahnmeister-I think I've seen your DIY ATO over at NR.com. Is it in the DIY sticky thread? The problem is that I don't have room for the RO storage tank, I might have room in my stand, if I didn't have any plumbing or a skimmer in the way. And 1 gallon isn't really worth it too me. With 1 gallon I'd be filling the ATO up every other day, instead of manually topping off my tank every day like I am right now. Thanks for the suggestion though.

areze-Thanks for the input. I'll definitely have to looking into TDS creep. And of course, I'm concerned about having an unlimited supply of freshwater. I figured I would run it on a timer so it only comes on for a short period of time, twice a day. That takes care of the float switch failing, but does not provide any sort of failsafe if the solenoid gets stuck in the open position. I suppose I would have to put in a second solenoid.

thirschmann-Could you explain a little more about how you have the auto flush setup? Sounds interesting, and thanks for the input on your setup.


So here's where I'm at...

Option 1. Move the Ro Unit, and run a line to to sump that uses a solenoid & float switch on a timer for auto topoff twice a day. 3 realistic options for the RO unit are hooking it into the washer's waterline, hooking into the water heater waterline, of moving it under the kitchen sink. But there's problems with all three. The unit itself measures 14x8x18. That makes for a very tight fit next to the washer, and we have shelves above the washer/ dryer. The first 2 rows of shelves are too small, maybe the top shelf would work. If I mount it under the bottom shelf, I have to move the washer/ dryer as far over as I could, otherwise the washer wouldn't open. Another problem with that my wife is looking into a new washer & dryer...so that's a bit of an unknown at this point. There's room in with the water heater, but I'm a little leery of hooking up the unit to this water supply. I have no control over when the water would turn on to fill up the water heater, and it could potentially turn on at the same time that the RO is running. Also, I'm not sure if there would be any issues tapping into that drain, which is a water/ pressure release drain. And lastly, the kitchen sink, easy install, but I've got to convince the wife to give up some cabinet space...which is at a premium. Plus running the line to the tank would be the most difficult from the kitchen.

And of course, there are concerns about the endless supply of water should something fail, TDS creep, and the shortened life of membranes with this setup.

Option 2-Trade my skimmer for something with a smaller footprint. Rebuild my sump so that it includes a section to hold FW RO. I figure I could get about 5 gallons with what I have currently on hand. Take out some room for the pump, and take out some room from the top as a failsafe (if the float switch sticks, it fills the tank until it reaches the top of the baffle, then the water flows back into the RO storage area. Still might kill off the tank, but my floors will be safe). So if you figure that I could get roughly 4 galllons total of usable topoff water, that would have me filling the topoff once every week-week & a half. I can live with that.

Option 3-Breakdown the tank...Not. Gonna. Happen.

Option 4-I don't know, I'm open to suggestions. The only other possibility would be to put the topoff tank in a closet that is across the hall from the tank. Running the water from there to the sump would be interesting, but maybe doable. I'll have to do some investigating on that today.

Thanks for all your input.

[ReefingBuddha]

the manual flush valve for my membranes was replaced with a solenoid with a built in timer (20 seconds), it comes on every time the system shuts down via the aquatronica controller, helping to get rid of the extra 'brine' and helps keep the membrane cleaner and prolongs its life.

Also I forgot to mention that in regular ATO mode I bypass 2 of the 100gpd membranes with ballvalves and t's so that it cuts down to just 1 so that water is produced more slowly and the membrane gets more use rather then just a quick start up and down of 3 membranes. When I do a water change I flush all three membranes and then use them to produce the water I need faster. I also have it set up that every time I do a water change I can switch which of the 3 membranes is used for the next 2 weeks until the next water change so they all get approximately the same level of use over their life time.

Hope that makes some sense, its seems overly complicated I know but I didn't want to add another storage tank. Get as much redundancy as you can afford if you go this direction.

[ckusnierek]

What ever you do, stay away from the AC soleniod and floats. AC and water could be DEADLY if there is ever a short... Also use a NC (normally closed) solenoid.
Mcmaster also sells 12v DC soleniods. and you can get a AC/DC transformer got under $10 you probally already have one laying around just make sure it's atleast 200mv.

That what I use hoooked tight to the RO/DI

I have 2 floats one for water level and another upside down at the top of the sump to shut off the soleniod if the #1 ever gets stuck.