AWC with two small pumps vs Neptune DOS?

[AtlCpa]

I'm in the planning stage of a 225g, ~300g total system going into a new house we are building. Water changes are something I'm trying to automate as much as possible of course.

I've read a lot about the Neptune DOS system a lot of people are using for Auto water changes. I have a couple concerns using DOS, the main one being how long the pumps have to run if you have a bigger system. The pumps would have to run for several hours a day just to change 2-3 gallons. That seems too long and I'd be concerned about wearing out the pumps and then inability to do a larger change if needed.

Is there reason I couldn't hookup two separate Eheim 500gph pumps (or something similar), one in the sump, one in the NSW reservoir and program Apex to turn them on and off to change water?

I know I'd have to figure out the calibration, how long to run each to get the needed gallons, need to turn off the ATO pump/sensor, etc, but is there a any reason you are aware of why this wouldn't work?

[ClownNut]

you can do that, i had setup this way for friend's setup for 5+ years now without any issue.
but, big system water change is not very effective way to deal with nutrients, if nutrients isnt an issue, then water change is not doing much. big water change do more than small water change.
i have a 400g system only do water change once awhile. i mean like 2-3 times a year maybe 50g/water change, mainly to siphon out crap build up in the tank.

[Eauturquoise]

Originally Posted by AtlCpa

I have a couple concerns using DOS, the main one being how long the pumps have to run if you have a bigger system. The pumps would have to run for several hours a day just to change 2-3 gallons. That seems too long and I'd be concerned about wearing out the pumps and then inability to do a larger change if needed.

Hello,

DOS Flow Rate: Variable (0.1ml – 250ml/min).
If I'm correct you need 15 minutes to change 1 gallon.

[tkeracer619]

Pretty risky. A lot of variables that will be hard to predict.

Do you have a floor drain accessible?

[gablami]

The main problem I had with using dos for awc is even at not-so-high rates, it was really noisy for my living room. I don’t know where your tank is located.

The problem with your idea of using two pumps is that almost inevitably, the head pressures will be different and thus will pump water at different rates, potentially drastically different. So your salinity will drop or raise depending. You could try to have it down to a science and adjust your salinity of the newly mixed salt water accordingly, but practically this is a pain in the rear.

Peristaltic pumps are much better for awc setups.


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[scuzy]

Originally Posted by gablami

The main problem I had with using dos for awc is even at not-so-high rates, it was really noisy for my living room. I don’t know where your tank is located.

The problem with your idea of using two pumps is that almost inevitably, the head pressures will be different and thus will pump water at different rates, potentially drastically different. So your salinity will drop or raise depending. You could try to have it down to a science and adjust your salinity of the newly mixed salt water accordingly, but practically this is a pain in the rear.

Peristaltic pumps are much better for awc setups.


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If you use two pumps you can have apex disable ato then take out a set amount of water then fill with new water to set point then turn ato back on.


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[gablami]

Originally Posted by scuzy

If you use two pumps you can have apex disable ato then take out a set amount of water then fill with new water to set point then turn ato back on.


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Ahh, like with optical sensors? Drain to this mark, and refill to this mark? That’s a cool idea.


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[scuzy]

Originally Posted by gablami

Ahh, like with optical sensors? Drain to this mark, and refill to this mark? That’s a cool idea.


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Gabe yeah that way your salt level never changes.


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