Turning on the return pump for the first time

[JoJosReef]

Silly post perhaps, but this is the first time I'm turning on the return pump of a tank with a sump and actual plumbing. You don't have to think about these things in the world of AIOs. Anyway, a couple of super novice questions:

1. Should I fill up the tank to just below the overflow weirs before turning it on, or do I fill it higher and let the water start draining into the overflow box/standpipes? I'm assuming the former since the latter would just drain into the sump with the pump still off. Right?

2. Do you start off with the gate valve (or ball valve, I don't know) more open or closed?

3. What are my primary goals with adjusting the gate/ball valve? My understanding is that it restricts flow a bit and may reduce noise--that still has me baffled, because the return pump is pushing out a certain gph of water into the DT, and the DT is overflowing back into the sump, but I can only imagine that restricting flow will cause DT levels to rise until flooding....

4. The sump currently has water up to about two inches over the middle section baffle (which is the same level as the return). Should this be higher for starting the pump? I'm thinking that the return might drain too much before an adequate amount of water goes into the overflow, but I have no idea.
Can kind of see the levels here:

I think I'll leave it at that for now. I might end up with more questions later. Thanks!

 

[RocketEngineer]

1) fill it until water makes its way to the sump. Then you can fill the sump directly until it is 1-2” from totally full. This gives you the max volume of water the system should have in it.

2) open. You want the system to be able to handle as much flow as possible.

3) by closing the gate valve, you are changing that pipe from carrying water and air to carrying just water (a siphon). This has the benefit of moving water without the gurgling noise. By getting the air out of the pipe, it can actually carry more water and so you are aiming for a balance. You want to carry as much flow as possible while preventing it from draining the overflow, pulling in air, then having to purge air and surge again.

4) yes, you want the sump almost totally full when you start the pump. 1-2” from the rim is my suggestion.

 

[JoJosReef]

1) fill it until water makes its way to the sump. Then you can fill the sump directly until it is 1-2” from totally full. This gives you the max volume of water the system should have in it.

2) open. You want the system to be able to handle as much flow as possible.

3) by closing the gate valve, you are changing that pipe from carrying water and air to carrying just water (a siphon). This has the benefit of moving water without the gurgling noise. By getting the air out of the pipe, it can actually carry more water and so you are aiming for a balance. You want to carry as much flow as possible while preventing it from draining the overflow, pulling in air, then having to purge air and surge again.

4) yes, you want the sump almost totally full when you start the pump. 1-2” from the rim is my suggestion.

Thank you!