Auto Top Offs

Birdlady · 03-16-2005, 09:56 PM

At my reef club meeting this week, and they all EEEKKKEED! that I have my RO/DI unit hooked directly to my float valve in the sump.

I do not have redundancy.

I do clean it and check it frequently.

Do I need to worry?

Matt Rogers · 03-16-2005, 10:53 PM

Hmmm well can you put a high level alarm or float switch that will act as a safety and turn it off some how if it gets too high?

Hmmm how to do that.. maybe an electric solenoid to turn the water valve off? Wow that sounds expensive. Not sure.

My tunze just has an audible alarm ... it's loud as heck.

JohnO · 03-16-2005, 11:52 PM

Sue,

Does the float valve cut off the household water supply or the output water from the unit?

If you have just a float type valve similar to what was ( and still is ) found in toilet cisterns then you may be asking for trouble. Not now, but certainly in the future.

John

Birdlady · 03-17-2005, 05:24 AM

John, yup a float valve like in the potty.

Hooked to the RO/DI which also has an auto shut off but needs back pressure to work, and that is hooked directly to the mains in the plumbing.

Asking for trouble...hmmm...that is not new for me! LOL!

szidls · 03-17-2005, 06:59 AM

Well my trouble started by my own stupidity.....of course. I went to do a water change on my 20 gal and forgot to power off the top-off. Do you see the problem??? I started siphoning detritus and didn't pay attention to the water filling back into the sump. Fortunatley I have my top--off water in a 5 gal bucket and not hooked directly to the ro-di. When I realized what was happening I went to un--plug the top-off and got my return pump instead. Error #2.

That's when Murphy's law came into play. The suction cups holding the top-off float switch came loose. I pulled the fill tube out of the sump and put it in a nearby bucket. I got the return pump plugged in before the sump overflowed. While watching the sump, the fill tube flipped out of the bucket and finished draining the last gallon of ro water on the carpet. My salinity changed dramatically and therefore I had to do a massive water change to correct it. Luckily all corals and livestock survived.

Needless to say, I have since marked all power supply cords and siliconed the top-off suction cups to the sump. I then practiced walking and chewing gum at the same time .

Scott

Birdlady · 03-17-2005, 05:33 PM

YIKES!

fletch · 03-17-2005, 05:42 PM

LOL szidls I thought things like that only happened to me LOL

beamer · 03-20-2005, 07:27 PM

Sounds a lot like me too!

Cindy

NUGIO · 03-25-2005, 02:47 PM

I had mine hooked up the same way as u birdlady.but it was goin on at least 4-5 times a day. more in the summer. I had read that the constant on/off pushed contamiates thru the membrane and ate up the DI bcuz of this.so what i did was get a 30 gal drum, put it in the garage on a sturdy shelf about 6ft off the ground and plumb the RO/DI to it w/a float valve inside so it auto shuts off when full.then ran the line to the sump.it lasts 2weeks in the summer b4 i need 2 refill the drum.never had a problem w/over filling.

BuckeyeFieldSupply · 08-21-2005, 04:01 AM

Quote:

Originally Posted by NUGIO

I had mine hooked up the same way as u birdlady.but it was goin on at least 4-5 times a day. more in the summer. I had read that the constant on/off pushed contamiates thru the membrane and ate up the DI bcuz of this.so what i did was get a 30 gal drum, put it in the garage on a sturdy shelf about 6ft off the ground and plumb the RO/DI to it w/a float valve inside so it auto shuts off when full.then ran the line to the sump.it lasts 2weeks in the summer b4 i need 2 refill the drum.never had a problem w/over filling.

Nugio - that is a great setup. The only thing I would modify is to size the reservoir to approximate 1 week's worth of top off water.

You could make the reservoir very large, but when the float valve fails all that water will gravity drain to your sump with obvious potential negative effects.

To avoid that potential, you could make the reservoir very small - but then you'd find yourself refillinging it requently, and experience the tds creep issue.

A good compromise for many people ends up being a reservoir that just slightly exceeds 1 week's worth of top off water. The reservoir can be refilled once a week, and its not so big that if all the reservoir water were to drain to the system you'd have salinity/overflow problems.