My Automatic Water Changer - Setup

[gmccreedy]

Why did it take a half hour to drain 5.5 gallons in the first place??

I have the drain hooked up to my canister outflow line. Once the normally closed valve opens, my canister forces the water down the drain line (I get a small trickle still in the tank, but gravity does its job and forces most of the flow down).

I drain about 10 gallons in 5 minutes. 1/2" solenoid.

Just wondering why your drain is so slow...


I like your idea except for one problem, the "normally open" solenoid will gum up with stuff from the filter eventually. This could effect the orifice of the solenoid drastically. maintenance would be required periodically to keep this from happening.

[plantbrain]

Originally Posted by gmccreedy

fish geek.

Have you seen this site? http://www.autotopoff.com/products.html

For solenoids, i used Asco valves. You can find them all over, but if you watch on ebay, you can find them dirt cheap. I think I got my first one shipped for less thn 15 bucks (1/2"!!)

You just have to make sure that you read the fine print and buy normally closed.

These are good, also, the snail guard and the dual float switch is wise, alway have a back up system with something like this or go semi automated where you switch things on/off when you are there to catch things.

It takes effort and thinking to do this and plumb things, however, look at the labor you save in the process and the total lack of motivation we often have that this saves you from?


I'd say it saves no less than 30-40 hours of labor per tank per year.
I have 5 tanks..........so that's 200 hours.
So if I paid myself 7 $ an hour, I'd save 1400$ per year. It might take me a few hours/weeks to set it up, but once done, not too bad from there on.
I'd still spend about 100$ per tank in material cost, but I'm still way ahead $ wise if labor is considered.

You can also set the system to do daily water changes, or 2x a week etc. So you can dose as much as you want.

Placing the drain and refill far apart also helps a lot to prevent in tank mixing.
There are dual set up where you can drain more %, but in general, draining a little slow(with more frequency) vs a lot fast(with less frequency) is better since it is no longer a labor issue.

But I do like to cean my tank with 50% of the water gone.

But that's gardening and I simply stop the refill part until I'm done.

The smaller % daily water changes also can avoid using dechlorinator or if paranoid, add a carbon prefilter to the refill line from the tap or use RO etc.

You can also hire a plumber to do this if you do not feel compent or hire a local friend to help that knows more about it(but don't plan on suing them if you flood your place

Regards,
Tom Barr

Regards,
Tom Barr

[plantbrain]

Sort of going along the lines of what Fish Geek was saying, you can oversize the drain for the solenoid, say 3/4", drain the tank in a few minutes, then have smaller inlet line to refill(say 1/4").

This will accommodate the larger % water changes without having a ot of flow coming back into the tank. Since the drain is much faster than the refill rate, you can time and set the drain to whatever desired level, say 50%. The refill tries to play catch up but cannot due to the oversized drain, but once it closes, the refill slowly fills the tank back up until the float shuts it off.

While 2 solenoids has options like this, you can do this with one solenoid, gravity and the pressure from the in line return can drain water as needed.
Same deal here, the return line that the float switch is attached to is small, say 1/4" and the drain is larger.

All you need to have is a float switch(refill) and a single solenoid for draining.
This can be done for about 50$ or less. Mechanical float switches work, but you can pay more and get these in the links above or a spectrapure electronic etc.

Such systems really work on central filtration set ups.
But then they typically have the filter near a drain and refill and have it hard plumbed anyway. So turning a few valves is all that's needed.

Regards,
Tom Barr

[fish geek]

Originally Posted by gmccreedy

Why did it take a half hour to drain 5.5 gallons in the first place??

I have the drain hooked up to my canister outflow line. Once the normally closed valve opens, my canister forces the water down the drain line (I get a small trickle still in the tank, but gravity does its job and forces most of the flow down).

I drain about 10 gallons in 5 minutes. 1/2" solenoid.

Just wondering why your drain is so slow...


I like your idea except for one problem, the "normally open" solenoid will gum up with stuff from the filter eventually. This could effect the orifice of the solenoid drastically. maintenance would be required periodically to keep this from happening.

Good points.

I wish I knew why the drain is so slow. The magdrive pump is rated at 250GPH. The Rainbird solenoid has barely allowed a trickle through when open though.

I had replaced the Rainbird with a Lawn Genie valve with lower flow rate requirement and placed the pump in front of the solenoid hoping for better flow that way.

No doubt using a diaphragm based valve is the problem.

I've seen true two way solenoid valves but none I can afford.

I replaced the white pad in the filter and will see if that makes a difference tomorrow.

[fish geek]

Originally Posted by gmccreedy

Why did it take a half hour to drain 5.5 gallons in the first place??

I have the drain hooked up to my canister outflow line. Once the normally closed valve opens, my canister forces the water down the drain line (I get a small trickle still in the tank, but gravity does its job and forces most of the flow down).

I drain about 10 gallons in 5 minutes. 1/2" solenoid.

Just wondering why your drain is so slow...


I like your idea except for one problem, the "normally open" solenoid will gum up with stuff from the filter eventually. This could effect the orifice of the solenoid drastically. maintenance would be required periodically to keep this from happening.

gmccreedy -

Well, I got it draining much faster with only two solenoids. It's closer to 5 minutes now.

The whole key is that the drain solenoid should be one designed for "gravity feed" applications. Solenoids designed for auto-topoff and sprinkler applications won't work for draining because they require high pressure to operate the diaphragm.

This ebay seller carries lots of different configurations. If you don't see what you want in his auctions, email him direct and chances are he has something that's not listed. The one I bought was $45.

http://stores.ebay.com/valves4projects

By the way, gmccreedy, could you please post a picture of your setup? Actually, I wish everybody would post pictures, it would help newbies like me to see all the different configurations...

[gmccreedy]

My Water Changer

The equipment setup is a bit different now, but the same stuff is used. I have the solenoids now mounted on the basement ceiling below the stand, and all tubing runs up through the walls into the stand. But it is still the same principle.

[jmhart]

For those of you refilling from an RO/DI and using an auto water change, how do you reconstitute your RO/DI? I'm guess you simply mix it in with your macro fertilizers and dose daily.

For anyone that does not use an RO/DI, but does use a auto WC, how do treat the water? Do you just dose prime via peristaltic pump?

[Wasserpest]

Peristaltic pump would be a good option.

I simply don't treat the tap water. In my case, there isn't that much Chlorine added, no Chloramine, and daily small water changes are not going to raise the Chlorine level as a 50% WC would.

Of course, everyone's situation is different.

[jmhart]

Yeah, I'm living in Atlanta where the water might as well come straight out of the backyard pool.