Hello,
I'm still in the learning process about my pool, thanks to this forum!
Currently, I' dealing with priming situation.
The schedule for the filter pump (turn on) is from 9am to 5pm. Once the pump start in the morning it taking long at high speed (RPM) before getting to regular function (1500RPM).
I think the issue could be related with the water returning to the balance tank after the pump is off. To validate this hypothesis, an overnight test was performed, closing the service valve for the tank (stopping the water getting out of the pump at this side). The next day, the water level at the pump gasket stay the same and not priming was required once the the pump started.

So, It's could be advisable to install a check valve in the balance tank drain pipe as show the picture below?

In case the proposal (based on the test) is good and the only cause, there could be any reason the builder didn't install the check valve? It could be a mistake during the building or the current schedule and setup is incorrect and the pump must be running 24h.
Other check valves are installed in the returns, immediately after filter, SPA return and edge pool. The pool return doesn't include check valve.
Thanks again for your valuable advices and comments!
---
Below some manual drawing in case the previous pictures are missing details.


I'm still in the learning process about my pool, thanks to this forum!
Currently, I' dealing with priming situation.
The schedule for the filter pump (turn on) is from 9am to 5pm. Once the pump start in the morning it taking long at high speed (RPM) before getting to regular function (1500RPM).
I think the issue could be related with the water returning to the balance tank after the pump is off. To validate this hypothesis, an overnight test was performed, closing the service valve for the tank (stopping the water getting out of the pump at this side). The next day, the water level at the pump gasket stay the same and not priming was required once the the pump started.

So, It's could be advisable to install a check valve in the balance tank drain pipe as show the picture below?

In case the proposal (based on the test) is good and the only cause, there could be any reason the builder didn't install the check valve? It could be a mistake during the building or the current schedule and setup is incorrect and the pump must be running 24h.
Other check valves are installed in the returns, immediately after filter, SPA return and edge pool. The pool return doesn't include check valve.
Thanks again for your valuable advices and comments!
---
Below some manual drawing in case the previous pictures are missing details.

