Automatic top-off/water-change design

[cartery]

Hi,

This is maybe more of a thought experiment. I'm not sure I'll actually implement this, or would even want to, but I thought of a design and I'm curious if people think it would work.

If I have a sump with a chamber holding the return pump, my understanding is that evaporation will only change the water level in that chamber. That's why you would put your ATO sensor/float valve in that chamber and not anywhere else.

So my idea was, you make another chamber with another pump and set up a reservoir with saltwater in the same manner as the ATO. You run that secondary pump to a drain or whatever. Then you trigger the secondary pump to lower the level of water in the second chamber which will trigger a refill from the saltwater reservoir, thereby doing a water change.

I'm thinking you'd probably need to pause the primary/return pump when running the secondary, at least to avoid triggering the ATO.

Does this make sense? No idea if it'd be worth doing, but I thought it was fun to mull over.

 

[Solo McReefer]

If you take out 1ml at the same time as you add 1ml

The level never changes

And will not affect the ATO

 

[Solo McReefer]

Alternately

And this is how I currently doing mine

Turn off the ATO, turn off the protein skimmer, turn off the in sump reactor, turn off the pump to the algae reactor, turn off the filter mat

Turn on the waterchange pump, pump out 5 gallons

Return 5 gallons fresh saltwater

Turn everything back on, except ATO

Fill with fresh saltwater to ATO level

Turn on ATO

Sounds complicated, but I just use a WiFi controller to push button all the devices

Eventually when I get the controller all set up, that will be one press

But invariably, when you do simultaneous water exchange, you are tossing out, down the drain, a small percentage of fresh saltwater. I don't know why, but that bothers me, I know it shouldn't

 

[cartery]

The approach your using is different in that it's not simultaneous, right? But otherwise very similar to what I'm saying?

 

[Solo McReefer]

You've added an extra chamber to your sump*

That I don't have

(*Hypothetical sump?)

 

[cartery]

You've added an extra chamber to your sump*

That I don't have

(*Hypothetical sump?)

Oh, gotcha. Yeah, hypothetical. I may have to build a mini version and see if what I'm thinking works. I'll follow up here if I learn anything