Hydros w/sump

[Cruzersmith]

I want to switch to a sump but am wondering if the baffle heights limit the % change to less than 10%? Not sure if I should shut off return pump and somehow use the backfill or just keep the sump level as high as possible to change more water, where should the low level sensor go if the ato sensor is in the return chamber. I thought maybe the refill water could enter the display tank but the ato sensor will shut refill down before the level above the weir is not as high as when the return pump is on so I doubt that’s the way to do it.

 

[wvned]

As you pump water out the ATO sensor should be dry because the return section will show the system volume loss just like it does with evaporation and the level will go down. If you pump out enough your return pump will go dry and can be damaged though.
You could do multiple water changes.
You could pump water out of the sump with the return pump off. You would need a water level sensor in addition to the ATO one in the return section. It would be placed at the water level in the sump when the return pump is off.
You can pump out water using a timer. It then refills back to the sensor at the sump full level. Then the return pump would be restarted and ATO function resume.
I use the timer function to do my water changes and a single water level sensor because my return section is very large. So the system reads full on the water level sensor and ATO turns back on.

 

[Cruzersmith]

Hey thanks for getting back. Just wondering why you time your pump out instead of using the built in ato/awc program? Just saving the cost of a low sensor? Your reply about doing the change with the return pump off is what I am asking about. I would need to separate the ato function from the ato/awc program and I have not seen if or how that would be done in hydros control. Every time I look it up I’m always referred to the combination program which won’t refill to the correct level .

 

[wvned]

The timer is part of the hydros ATO/AWC programming and already there as an option. Then you do not have to have a low water sensor.
The drain pump and NSW fill pump is plugged into hydros like the ATO pump
AWC starts. ATO shuts off, drain pump runs set number of minutes, saltwater is replaced back to water level sensor by fill pump, ATO resumes.
Since my drain pump moves 1 gal/min I just set how many gallons I want out by how long the pump runs. I only have to change the program a bit if I want small daily changes or one large one.