Are you sure that this method will work? It seems like there's no flow back to the pool and you may have to change some valves. Anyway, I don't think that anyone can find the right way out without seeing this installation in reality. Therefore, you better call https://goldcoastplumbingcompany.com.au/, for help. I always appeal to their services when it comes to plumbing, as they're the best in town! Don't worry about the costs. You'll know the price before they start to work, because they have unique fixed pricing on all water services. Honestly, I'm really pleased with this company.