Two Pumps (Main + Solar) Pump Setup Issues

[dr_harika]

Hi, I recently bought a house with a green cloudy pool, and have had to learn everything via Youtube + this forum!. The pool is now clean and clear. Thank you!.
A few weeks in, i am convinced there is some issues with the pump configuration, but thought i'd ask here.

Climate: I am in Melbourne Australia, freezing is not an issue as we dont get below 0 degrees.
Pool Info: Oval Pool 40,000L + Spa 2500L, Salt Chlorinated, Solar Roof Heating, Gas heater has been disconnected permanently
Pool has 1 Return Jet, 1 Skimmer Box (which has a 2nd pipe in there that appears to be the main drain), Spa has a drain + 4 jets (1 barely works)

Pool Setup:
Nothing is better than posting a photo of the setup so here it is (I have annotated, but this is from my own research, so it might not be 100%)

I cant seem to embedd the picture, so have linked it to my imgbb direct to image.
https://i.ibb.co/rm32xz1/20210711-12491 ... iagram.jpg
https://i.ibb.co/rm32xz1/20210711-124915-Pool-Diagram.jpg

So my issues/questions:
1) Does this setup look right to you? I haven't come across a two pump setup like this (Main Pump + Solar Heating Pump).
2) The Solar Heating Pump doesn't work by itself. It needs to have the main pump on too otherwise no water circulates to the pool. If the Solar Controller turns the pump on and the main pump is off, water doesn't move. I have turned off the solar controller to avoid the motor burning out.
3) When i turn the main pump on (currently manual), sometimes the pump starts and water barely flows (high pressure shows on the sand filter). I have to turn off the pump, depress the lever on the sand filter until i hear some water gurgle (so a very very light depress only) , and then i turn the pump on. It will then prime perfectly and be in range for pressure.
4) When the main pump turns off, everything that was caught in the skimmer basket gets pushed back out into the skimmer box and the skimmer filter sock inverts.
5) Is it possible to also have the Gas Heater re-connected and install 3 Way valves so i can select from Roof Heating (Summer) or Gas Heating (Winter, only for Spa use)
6) The Spa Blower has 2 options, but both make the spa bubble up. Any ideas?

Any advise is appreciated.

[Denniswiseman]

I take it that the pipe between the solar flow and return is straight through therefore when the solar pump is the only one on, it just circulates along the flow and returns and solar collectors and doesn't go anywhere else
When the main pump is on as well the solar flow pulls out of the main flow and returns to the same pipe but is being pushed on to the rest of the equipment
It does look like you could do with some modifications and automation with a divertor valve immediately after the filter linked to the solar so if it's calling for heat it will divert to solar and operate the solar pump. (Your main pump may not be man enough to do it alone
A Non return valve (NRV) on the main pump suction side will stop the blowback and hold prime
You can add a gas heater but will need valves and bypass to link in

Hope I've helped

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[dr_harika]

Thanks for the reply Denniswiseman. I have now configured the solar controller to turn the main pump on for filtration, and then only if the main pump is on to turn the solar pump on (if heat is needed). This now makes sense after digesting your reply.
I am in the process of dismantling some of the pool equipment to accommodate a new salt chlorinator and noticed those beige items (one straight after the filter, and one before the salt chlorinator are non return valves), but they dont work as there is no rubber seal, and one was broken off its hinge.

I am taking the opportunity to optimise the setup, so can i ask how many check valves you would put in? I am thinking 4?:
1) Suction Side of the Main Pump, 2) Directly after the filter, 3) On the main line between where the solar is taken off, and where it comes back in, and 4) before the salt chlorinator

Also, while dismantling, the inside of the pipe seems to have a deep orange residue. Is this normal or am i dealing with some sort of algae?.

[Denniswiseman]

I don't think you need all those NRV's. Can you mark them on your diagram
I don't know what the orange deposit is but I don't think it's algae

[dr_harika]

Sure, here it is. Orange Circles are where i was thinking. I worked out how to attach pictures this time from seeing your reply on another thread.

[Denniswiseman]

I can see what you are trying to achieve and the one between the solar flow and return will stop the short circuiting
Is the one on the SWCG flow an existing one that was faulty

[dr_harika]

I can see what you are trying to achieve and the one between the solar flow and return will stop the short circuiting
Is the one on the SWCG flow an existing one that was faulty

Yes,2 of the ones I've marked are replacing failed existing ones (the one after the filter and the one before the SWCG). The 2 I'm adding is the one on the suction side of the main pump and the one between the solar to stop that short circuiting.

I haven't mentioned this previously but my pool equipment is around 1m higher than my pool.

[Denniswiseman]

The height isn't to bad but the NRV before the pump will keep your prime