How to plumb an automatic water change system!

[Anthony Calfo]

Thanks kindly, Tom... but yes, your question is off topic. The title of the thread is "Automatic water change systems." Please start a new thread for such topic if you cannot find the answer in the archives.

I'm not even sure what exactly your question is here, my friend. Do you want to drill a tank that is full of water? You'll need to drain the tank indeed. The stress (resonance) of the water and its weight/force are a risk to that tank integrety otherwise.

As for the hole saw... just notice the mfg details on the saws available at the local hardware store (for metal, for wood, for plastic, etc)

[Casperson]

Thanks Anthony,
Sorry about the thread issue.

[Kathy55g]

In a previous post we were talking about how to prevent the emptying of the sump in the event of a powerfailure. solenoids are complicated and expensive as a turning off mechanism. I recently thought of those battery operated garden watering timers that you hook your sprinkler to. They are not very expensive, and can use standard hose fittings, and will open and close the sump drain on a timed schedule. These fail closed, so if the batteries wear out, you are OK, if the power goes out during water change time, you are out of luck, but what are the chances of that? You can schedule the water change for a time when you are likely to be home, so that you can manually shut down if needed.

Just a thought.

[Anthony Calfo]

they operate witht he same principal, my friend... both fail off.

yet the garden hose option is lower quality... not something you want to run your expesive reef and live animals on.

And worse... the batteries require a level of ongoing maintenance that not everyone will remember to do.

I do feel strongly that you get what you pay for with an industrial solenoid valve: quality and reliability.

[enigma32]

[first post]

What solenoids do you folks typically use?
i.e., what manufacturer? Is the solenoid plastic?

I did a quick google search and found mostly solenoids intended for CO2 injection.

How do the solenoids stand up to the water?
I've worked with brass solenoids in salty water environments (they typically lasted 4-5 years, sometimes longer), but in a very different situation than a reef tank.

[dandy7200]

I would love to see some pics of this system!

[skeeter_ca]

Wow, Complicated thread was hard up with but i think i understand. I have a semi-automatic water changer and top-off on my tank. Since i don't have a drain lower than my sump i use a pump to pump the water out of the sump to my laundry drain and then a top-off switch to turn on a return pump from my SW reservoir. If i leave my main pump running i can remove 4 gals then replace with 4 gals of new SW from a reservoir in the garage without distrubing anything. Could be made automatic easily with timers. If i shut off my main pump it can change 14 gals + another 3 if i pull my durso and let the overflow drain. I can also turn on both pumps at the same time and exchange all of the water in my reservior and the new SW inlet is at the pump outlet of the sump, so the new water has to go through the entire tank before it comes to the old SW out pump.At first I designed it to be automatic but now i like being a part of it as it helps me stay close to the tank and see whats going on.

[porthios]

i'm really sorry to dredge up such an old thread but since it's referenced in the stickies i feel i have to point something out. the solenoid on the wcd is not going to save you from draining extra water in the sump due to a power outage.

best case scenario, power is cut to the return pump and solenoid at the same time. power is then restored to both at the same time and they race to empty the extra water in the sump. the return pump at whatever rate it flows and the wcd at the max rate it'll flow (1" = 600gph, etc..). you'll suffer less dilution than w/o the solenoid for sure but you don't eliminate it..

worse case, power is not cut/restored to the return pump and the solenoid at the same time (wired on different circuits, breaker trips on return pump).

worst case, chuck norris doesn't like you but that's another thread..

i should point out also, that power is often lost and restored a few times during a home's power outage, so a week of storms while you're away on vacation might result in quite a bit of dilution with ro/di..

in the end, i think kathy55g gave up too easy . there's no reason her method can't be automated with a proper controller

1. cutting power to the return pump
2. allowing time for extra water to settle in sump
3. pumping new water into the system and overflowing excess through wcd
4. restoring power to return pump

i think i've talked myself out of automating water changes now i'll just strive for 'easy as possible to do manually'. i don't think the automation ends up buying you that much in the end..

[reverendmaynard]

What about the 2 channel dosing pump method? One channel is pumping water from the reservoir into the tank, the other channel is pumping water out of the tank and into the drain.