I have just added a peristaltic pump to my DIY tank monitor/director. It is a raspberry pi with Atlas Scientific probes and pumps and has been working flawlessly so far.
Right now, the ATO function is set to add RODI water in 5mL amounts every minute as long as the salinity measures >35.1ppt. I will eventually be putting a water level shutoff on this as well just in case something goes wrong but for now its been reliable and safe (I only have a 1gal RODI reservoir to limit any catastrophic failures of the system until my water level shutoff is in place).
Anyways, I would like to implement an auto water change system using a second pump and two containers (one empty for dirty salt water and another with fresh salt). These pumps are not cheap so I am wondering if it would be a good idea to run one pump with check valves and just run the pump in reverse to remove water from the tank (check valve opens to the empty container and closes to the fresh water container) and run it forward to add fresh water to the tank (check valve closes on dirty water container and opens on the fresh salt water container). This way I could run the pump alternating between forwards (fresh water in) and reverse (dirty water out) in 100mL stages to change out as much water as I want.
Is this a bad idea? I have attached a quick diagram to indicate what I am talking about. There would be some "overlap" of the two solutions (dirty and fresh salt water) but I could tune that out by adjusting the amount that each stage doses.
Right now, the ATO function is set to add RODI water in 5mL amounts every minute as long as the salinity measures >35.1ppt. I will eventually be putting a water level shutoff on this as well just in case something goes wrong but for now its been reliable and safe (I only have a 1gal RODI reservoir to limit any catastrophic failures of the system until my water level shutoff is in place).
Anyways, I would like to implement an auto water change system using a second pump and two containers (one empty for dirty salt water and another with fresh salt). These pumps are not cheap so I am wondering if it would be a good idea to run one pump with check valves and just run the pump in reverse to remove water from the tank (check valve opens to the empty container and closes to the fresh water container) and run it forward to add fresh water to the tank (check valve closes on dirty water container and opens on the fresh salt water container). This way I could run the pump alternating between forwards (fresh water in) and reverse (dirty water out) in 100mL stages to change out as much water as I want.
Is this a bad idea? I have attached a quick diagram to indicate what I am talking about. There would be some "overlap" of the two solutions (dirty and fresh salt water) but I could tune that out by adjusting the amount that each stage doses.