Gravity fed FW top off system

[Untamed12]

In your opinion, will this work for evaporative replacement?

- 100 gallon tank at a height of 3 feet holds RO/DI water. Maximum water level in this tank might be 6 feet high.
- 1/4" tubing runs from bottom of 100 gallon tank to Kent float valve in sump.
http://www.jlaquatics.com/phpstore/store_pages/details/rounits.php?product_ID=ro-kpfvalve

Do you think the float valve would be able to stop the water flow?...or would the water pressure from 100 gallons through the 1/4" line be too much for the float valve?
Would such a system adequately replace evaporated water in a 400 gallon system?

Is anyone using a straight gravity-feed evaporative replacement system that works?

 

[Untamed12]

No one using gravity feed water top-off?

 

[OldmillXxX]

I normally use that, but have recently just hooked up the output of my DI to my float valve. My house has a PSI of about 80, so I figure gravity feed should work just fine. Works great!

I never can understand why people continue to fight float switches and such. Simplicity is the key, for me at least...

I should note that I do throttle back the pressure with a small valve just so the float valve will hold better without working so hard.

 

[Untamed12]

Any other comments?

 

[h20cooled]

I use a gravity feed top off, but it is not directly connected to my RO/DI unit. basiclly I have a 35 gallon container in the garage that is filled with RO/DI water and then I add Pickeling lime to it for Kalk water, there is also a small powerhead in there that comes on every couple of hours to keep the kalk stirred up. The line runs under my house and up to the 2 SW tanks through float valves.

I've always been concerned that one of the valves would stick open and dump 30+ gallons of water into the tank. But after 2 yrs of using them it has never happened, the worst was one of them got stuck closed and I almost ran out of water. But that is easy to fix with routine cleanings. If you watch the way the water comes out of the float valve it drips, so it would take a lot for it to get stuck open considering that its never fully open. I think the worst case is it would get stuck in a constant drip...

Rich

 

[BeanAnimal]

I would put another container in between.

My RO/DI fills a 5 gallon pail. The pail fills the tank.

The pail only fills when it is empty. This is done with a latching relay circuit and float switched in the pail. The pail is filled via a solenoid through a FLOAT VALVE. The float valve is above the control float switch and adds an extra layer of protection of the solenoid sticks.

The pail fills the sump through a float valve as well. In this case there is a float switch just above the float valve, it is in series with the solenoid. If the water in the sump rises to high due to a leaking float valve, the solenoid closes (if it is open) and the most water that can drain into my sump is 5 gallons.

You could setup a similar intermediate holding tank that is filled from your 100G resevoir. Make the holding tank small enough that it can not overfill your sump.

I can offer more details of this sounds like something you wish to learn more about.

Bean

 

[DanielMar]

Re: Gravity fed FW top off system

Quote=
Do you think the float valve would be able to stop the water flow?...or would the water pressure from 100 gallons through the 1/4" line be too much for the float valve?
End Quote

Untamed12
Not sure if it will have enough pressure for you.
I doubt if the pressure would be adequate. Static water wil have a pressure of .4333 per foot of height. So, 6 feet high of water in any sized container (i.e. 100 gal. or 1000 gal.) is 2.5998 psi. & 3 feet is 1.2999 psi.
BTW, I use a Kent Float valve in my sump but, h2o pressure is 60 psi+.
Hope this helped. Not sure if it will work @ 3 psi. Even though I believe it will work, just not fast.

Let us know

Daniel