Tank automation ideas

[gogol]

I have thought a lot about of auto water changes and was actually thinking of taking it a step further...

Assuming that we are running a skimmer and carbon/phosban, isnt the water you are taking out your tank .. basically salt water depleted of oxygen and consumable minerals?? (ok I concede there might be some uglies as well, but it should really low if your filtration system actually works)

What would be the result of feeding the 10% drained out water to an RO/DI unit? Shouldnt we get RO/DI water back ? If not could some one please explain which ions (organic and inorganinc) /particle can pass through.

If we do get standard RO/DI water back, wont this habit really go a long way in conserving water ? Just thinking aloud ..

 

[steamman]

Don't you loose a large percentage of water processing through an RO unit ??? How about this for auto water change. I don't know how your tank operates but you should get the idea. Drill a hole low in your sump. Enough to drain say 20 gallons if opened. Install a solenoid valve on a timer. When the timer activates the solenoid you drain your water. Now the solenoid closes and another timer turns on a pump from your mix tank. You install a float switch in your mix tank to shut the pump down when the water is pumped out. Make sure you install an air gap on your fill to the sump so the water does not syphon back to the mix tank. This only needs to be done if the mix tank is lower than the sump. There you have it. Water change with no diluting. This trip is getting complicated. Are you sure you want to go? Just kidding. Good luck with it. Making thing too complicated, especially if unproven, would make me nuts while I was away.

 

[redfishbluefish]

Steamman is right. RO works by running tap water constantly over the filter membrane. I don't know the actual numbers, but just seeing the unit I have, I'd guesstimate that for every gallon of RO water, at least two gallons go down the drain. For a while I was running the waste line into an empty washing machine to at least use that water to wash cloths.

The other consideration is running that dirty water through you RO unit...you will quickly saturate/clog some of the filters and, my guess, shorten the lift of the RO membrane.

Definitely no water savings and most probably an increase cost in filter changes. However, I do like your thinking.

 

[Nickjr000]

The way i have the bulkhead in the sump it's right above my running water level. The fresh saltwater pump kicks on and simply overflows the sump and the excess water goes out the bulkhead and down the drain. Works great. I wouldn't try to do anything to drain the water in your sump or tank lower and rely on a pump to fill it back up. Because if the pump fails to kick on to refill it you risk running dry( Assuming you don't have ato or if it malfunctioned). I think my concept of overflowing through the bulkhead is good because you don't have to worry about your refill pump sticking or if it ever stayed on it won't overflow out the top of your sump instead it goes out your bulk drain. Just mt 2c

 

[steamman]

Your method is pretty fail safe and simple Nickjr000.

I was just rattling off something that popped into my head when auto change came up. The way my system operates what I mentioned would work for me although I forgot that you would need to cut off your return pump.

I would drain the main tank into the sump via the overflow and down to a predetermined level (new hole in sump). The DT would stop flowing because, I forgot to mention, you would need to cut off your return pump with a timer before the solenoid was activated to drain your sump. Everything else could stay the same with the timer on the mix tank and the air gap.

My point really is that the more you install the more things can go wrong. The more equipment you add the more that can malfunction. Anything mechanical or electrical is not guaranteed to work forever. Things do fail.

I have gone away for up to 15 days at a time. Every time I go away I come up with something a little better for the next time I leave. I do keep it as simple as possible. I still have to rely on the same equipment as everybody else. I just try to limit the complexity of it all.

 

[gogol]

Nick, how do you make sure that the overflowing water is the old water and not the freshly added one? The only way I can think of is:
1. Shutting sump off from DT
2. Adding the fresh water at a distinctly lower temp than water in the sump so that it settles down and pushes the old warmer water up.
3. Let water in the sump sit for a bit to allow heat exchange
4. Connect back the sump and hope your pump does the remaining job of heating the colder newly prepared salt water.

You actually might have salinity issues with though

 

[steamman]

That was kind of what I was saying.

 

[Nickjr000]

Steamman you said it perfect.... the more stuff you add the more to go wrong. I kinda came up with this myself and so far that's the only kink I can't get out. If you just let the fresh water enter your sump right over your pumps intake to the dt then most of it will stay in the dt. I'm guessing. But even so, if you pump 15 gal of new water into a system of 200 gal or so and have it go to the dt and mix with your old water before it goes to your sump how much is really going to go out the overflow bulkhead drain? Not a lot. probably less than a gallon. This is still a project in the making. Btw.... If you do this don't plumb the drain line into your sewer because if it ever backs up the sewer water and waste will wind up in your sump then your tank.

 

[Tazmaniancowboy]

Nickjr, I like the idea and may kick around the idea for my system. Thanks

Taz

 

[Nickjr000]

No prob