How to auto water change?

[neopode]

This may be a stupid question but how do you set-up the pump situiation for auto water changes?

I have have the AutoAqua AWC which reads the levels of the water using two optical sensors and the redsea E170. I have it all plumbed and set-up with the two sensors reading the main tank's level and the drain pump in the AIO back sump. This doesn't work great.

My question is how do you get more than the sump volume for the water change? The sump for the E170 is only around 3 gallons, so my water changes are ~7% (trying to do 10% weekly).

Do ya'll actually have the drain pump inside the main portion of the tank? Do you put it in the main portion when doing WC and then remove it? Maybe some piping for the E170 where you can create a siphon lower than the overfill?

Thank you in advance!

 

[killer2001]

With an AWC system you should have water coming in and water going out at the same rate, so two pumps running simultaneously. The Max E-170 has an 8 gallon sump (37 gallon display).

 

[neopode]

With an AWC system you should have water coming in and water going out at the same rate, so two pumps running simultaneously. The Max E-170 has an 8 gallon sump (37 gallon display).

The autoaqua AWC does not operate this way.
It first drains the tank to optical sensor 1, and fills to optical sensor 2.

Maybe my drain pump isn't bottomed out when draining? I turn off the return pump and the sump pump and the most i've drained was 3 gal before it started to make air noises. There is a bunch of gear in the back (the protein skimmer, pumps, media bags, etc) maybe that is taking up some of the missing volume?

 

[killer2001]

So I would set up the optical sensor 1 and 2 to only remove 1 gallon. Then perform this X amount of times to change out the amount of gallons you want to replace. For example, when it's time to do your weekly water change, and you want to change out 5 gallons. Perform the 1 gallon change 5 times.

 

[neopode]

So I would set up the optical sensor 1 and 2 to only remove 1 gallon. Then perform this X amount of times to change out the amount of gallons you want to replace. For example, when it's time to do your weekly water change, and you want to change out 5 gallons. Perform the 1 gallon change 5 times.

This is a great idea! I could set it up for 2 gal every 3 days.

Will this affect water chemistry or it largely doesn't matter over the course of months?

 

[killer2001]

I think 10% weekly is a standard (and safe) change interval. For me personally, I do 2% daily and it seems to be working out well so far.