I am a new pool owner and am just getting started maintaining my pool. It is currently an algae filled nightmare. I have zero experience with pool maintenance besides brushing and chlorine tablets. So today I started using the BBB method based on measurements I got from the Taylor testkit I just got.
I am supershocking my pool today with plain Clorox bleach and am running my filter. Today is the first time I started paying attention to the pressure gauge and I am worried it is too high. It is around 20 psi and I'm not sure what it was when I'd run it previously. From searching the internet it seems like 20 is on the high side. The skimmer is running fine but the robot vacuum is immobile for the most part. It's feet are kicking but it doesn't move. I'm worried this may have something to do with too high pressure in the filter but I'm not sure. The robot has moved fine previously but I've noticed that it stops moving either a) when it gets stuck on the wall or b) after the pump has been running a while, it just sinks to the bottom of the pool.
So, I tried backwashing my filter for the first time today and lo and behold water came shooting out of the cut off line labelled with the red arrow. I turned the pump off quickly and put the filter back into filter mode. The pressure remains around 20.
Here are pictures of my setup. I am thinking that the red valves may have something to do with redirecting the water into backwash mode but I'm not sure. My questions are:
1) How do I backwash correctly? Do I need to connect something to the cutoff line or will moving the valves get me into backwash mode?
2) I have a DE filter. After backwashing do I need to fill it back up with DE? If so, where's a good place to buy DE?
3) How do you determine whether the DE filter just needs a backwashing as opposed to a full on filter clean with opening up the top?
I really appreciate your help.