Automating Water Change in Fish Room-Sprinkler Valve

[woodenfish]

Is it true that the ordinary sprinkler valve does not work on RO water because the flow rate is typically too slow?

Do valves that work on diaphram function in RO line to feed into tank?

If not, is there inexpensive valve that will work for slow flow rate?

How do you automate water change with RO water?

Thanks

[woodenfish]

If the sprinkler valve works, I think it has a better chance of working if it is hooked up at the input to the RO.

At least, RO plus waste is about four times RO alone. I think there is a 1:3 ratio. So if the RO flow is 2GPH. the intake would be about 8GPH. Still quite slow though.

An occasional very small drip irrigation system may be just 10 GPH or so. Don't people use sprinkler valve for small drip irrigation system? Hope it works.

[Polar_Bear]

Woodenfish,
I'm not entirely sure what you are asking. If you want to shut the flow off automatically to your RO unit simply put a solenoid valve on a timer before the unit. If you want to fill a tank and then have the RO shut off, a simple float valve will work for that.

[woodenfish]

Woodenfish,
I'm not entirely sure what you are asking. If you want to shut the flow off automatically to your RO unit simply put a solenoid valve on a timer before the unit. If you want to fill a tank and then have the RO shut off, a simple float valve will work for that.

Thanks

I will not be relying on any level valve to shut off the RO water; I will be drilling and putting a bulkhead for overflow. The water level will be absolutely decided by the plumbing. The water change will be based on time. This is not efficient in water use but is safe. Overflow will drain outside the house.

I want to shut off the RO water after so many hours. I will be using a sprinkler timer.

I know that the plunger on a typical sprinkler valve is a solenoid, but a typical sprinkler valve does not use the plunger to open and close the valve directly. There is a diaphram inside. The solenoid lets air in and out. I think the movement of the water then opens or shuts the valve.

I think if the flow rate is too low, a typical sprinkler valve may have problem opening and closing. Am I right?

[Polar_Bear]

I don't think so. I've used the same type of valves in my garden running drip systems, no matter how low the flow the valve always worked, so I think you will be fine using one. The diaphagm is for water "pressure" not flow. So if your water pressure is high enough (and it should easily be) you will have no problems.

[discussmith]

I use sprinkler valves on my 100 GPD R.O. , my cold hard tap water storage system, and my warm softner water direct tank fill system. This allows me to use float switches with 24 volts to turn the sprinkler valves on and off. They are also inexpensive, about $10-$12. I have never had them fail. This is important because you can read here of the numerous accounts of us who have started water changes become distracted and suddenly remembered when jogged by the sound of water splashing on the carpet! The valves do require house water pressure to function properly. They will not work with aquarium pumps feeding them. They won't open.

[woodenfish]

After browsing on ebay I think that most sprinkler valves are pneumatic solenoid valves, not "direct" solenoid valve.

The solenoid of the sprinkler valve is a plunger that opens and closes a small hole that lets air in. The diaphragm then opens and closes the valve for water. So water pressure has to be high (and I thought that the flow rate matters as well)

For low pressure, like drain from just a foot of water head, a sprinkle valve will not work, I think, so a direct solenoid valve is needed.

I also found out that direct solenoid valves on ebay are not very expensive, only that 24 VAC coil solenoid is not common. 24 VDC and 120VAC are more common. The transformer that comes with most sprinkler timers are 24VAC, as sprinkler valves use 24VAC. This means that I may have to use a 24VAC relay.

[woodenfish]

Rain Bird Sprinkler valves actually list the specs

min flow 0.2 gpm or 12 gph
min press 15 psi

15 psi is quite high and will not work with just a few inches or even two feet of gravity fed drain.

12 gph is marginal. If I put the value on the input, than 100 GPD RO should use about 300 GPD RO, water plus waste. close to 12 gph.

[2sybs]

Would a dishwasher solenoid valve work as well?
They are quite a bit smaller in size than a sprinkler zone valve.
The only problem would be the voltage required.

[dishpanhands]

Would a dishwasher solenoid valve work as well?
They are quite a bit smaller in size than a sprinkler zone valve.
The only problem would be the voltage required.

dishwasher solenoids will burn up if on for very long time. They don't have a long duty cycle. would be the same if you tryed to use a Ice maker water valve..

I use the 24 volt water valve from

http://www.jehmco.com/html/float_valves___switches.html

They can be left on for many hours without any trouble.

[2sybs]

dishwasher solenoids will burn up if on for very long time. They don't have a long duty cycle. would be the same if you tryed to use a Ice maker water valve..

Ok I was suggesting it more for the compact size as a sprinkler valve can be a bit on the bulky side, but then I have dealt with more failed/stuck on dw valves than i care to remember and don't recall ever having a sprinkler valve stick on, more likely they will fail to open.
And though nothing is fool proof, (I have also had to deal with the flood after a float valve failed to seal.)
So after thinking about it I am liking the idea of using a sprinkler zone valve more and more.

[woodenfish]

I just rec'd my 3/8 NPT solenoid valve.

It turns out that it only has a 1/8 orifice. This is fine as I plan to use it for high pressure input to fill the tank.

But to drain I had planned to use a 1 inch NPT solenoid valve. Now I think even a 1 inch solenoid valve will have a very small orifice and wouldn't work.

I think one needs a very large solenoid valve for draining aquarium water, as a small orifice would likely clog. Too expensive, not feasible.

[woodenfish]

I think I will just use manual valves for drain.

I'll use rather large plumbing, likely one inch, so I don't have to wait very long. Just stand there and wait a minute or two for one-third of the water to drain.

I will set the solenoid valve to start and stop at certain times. Then I will just set an audio alarm ten minutes between filling starts. I will just drain and then close the drain valve and walk away.

[dishpanhands]

Jehmco has low pressure solenoid valves that has hose barbs on it..
http://www.jehmco.com/html/float_valves___switches.html

[woodenfish]

I think to drain aquarium water one needs at least 1/2" of actual passage.

No matter how well one screens the drain water, drainage smaller than 1/2 inch is subject to clog, wouldn't one agree?