Two small return pumps for AWC vs DOS...why not?

[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.

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. The pumps would have to run for several hours a day just to change 2-3 gallons a day. That seems too long and I'd be concerned about wearing out the pumps.

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?

 

[Wrasse-cal]

Good question. Bump for an answer from someone more knowledgeable.

 

[WWIII]

You would probably have to run it using sensors and/or float switches. I don't think the pumps will be able to mirror eachother accurately enough. Plenty of guys do awc with regular pumps vs dosers, but I think most use sensors and/or float switches.

 

[Breadman03]

The main challenge with an AWC is balancing the in and out flow. The DOS can do a pretty decent job of it, but yeah, they're peristaltic pumps. Don't get me wrong, mine spent a couple years running without maintenance. The only exception is that since I got them in the initial release, I got replacement pump heads shortly after putting them online because the heads would crack and fall apart. I know, I should really replace the tubing....

Anyhow, you should look into the Genesis Renew. I've seen positive reviews about them.

 

[AtlCPA]

Thanks for the feedback. I keep going back in forth on this issue. Ultimately I think I'd like to have the small return pumps and the ability change more water as needed still by just turning pumps on and off.

The other advantage of DOS I'm finding is being able to run the tube down into my mixing tank vs if I had to put a small pump down in the new saltwater, it would need to be in a new container, not the mixing container. Meaning I'd need three containers.

I'm assuming a small pump at the bottom of the mixing tank wouldn't be a good idea for the wear and tear on the pump. Maybe that's not an issue though.

 

[ca1ore]

Peristaltic pumps are very good at precise dosing, so setting and maintaining calibration is pretty good. Regular impeller pumps, not so much. Absent sensors, level switches, etc., I suspect you'd not be able to achieve adequate balancing.

 

[AtlCPA]

ok, good to know. I'm thinking I'm going to have to just turn this part of the project over to the LFS crew, explain what I'd like to happen and let them work their magic. I'm more likely to flood my basement than automate my water changes.