Need some help advice and guidance from the experts on this forum.
We just became first Time homeowners and bought a house with a pool. We inherited a 15-20 year old Pentair System 3 DE filter system. Right after buying the house I found that the pool was operating at high pressure 40-50 psi hence I opened up the filter and cleaned up the grids. Also Replaced the Orings and did all the greasing required for equipment maintenance. I also had to replace a few broken jandy valves. As a result of all this maintenance, the standard pressure of 20 psi was achieved and the pool was running like a champ. About a month later the same high pressure 40-50 psi started to be seen again and I again cleaned up the filter system. Again the pool ran like a champ at standard operating pressure if 20 psi but only for 15 days this time before the old high pressure symptom came up. Again I cleaned up the filter system because tuis go round there was a huge storm where I live and lots of leaves had come in the pool. So I though the filter may have become dirty.
Now I find that I need to back wash it every day because the pressure is 40-50 psi by the end of the day. Basically if I backwash the pressure falls to 20 psi and then after about 2-3 hours of running the pressure rises to 40-50 psi.
I know I am doing a few things wrong or have not done a few things such as
1. Not replaced DE in the filter - I read on this forum that DE is what cleans the pool and in the absence of DE the grime in the water can clog up the grid and thus increase the filter pressure as the pump is now fighting against the grime in the grid. Back washing dislodges the grime temporarily but then the grime builds up again (AM I RIGHT INTHIS ?)
2. Have tested the water with a basic kit but not the kits recommended on this forum - saying this because reading this forum is telling me that there. Oils be algae in the pool which is not green but they go in and clog the filter. Just for reference, my pool water is not green at all it is quite clear. But each time I open up the filter to clean it there is that grey muck clinging to the grid.
3. Have not fixed two leaks in the poll system - one leak is where the Polaris system connects to the Polaris pump and there's another one at a joint
Given the above situation can someone help me with the following questions
1. Given that I need. To replace DE, how do I replace the DE- through the skimmers or by opening the filter?
2. How do I test if this is an Algae problem - I don't see any green stuff but this forum seems to suggest that it can be a Algae problem? Should I go to Leslie's and get my water tested and share the results with the experts here on this forum to ascertain if this is Ana Algae problem?
3. Could the leaks be creating this as in somehow an air pocket is being created but then leaks are supposed to reduce pressure not increase it if I am right?
4. What advanced test kit do I need so that. I do not have to go to Leslie's for water testing? Asking because every time I go to the local Leslie's they tell me the. pentair system 3 is 20 years old - you should spend the money to replace it, why are you trying to maintain it on your own get professional help and all.
I really want to fix this on my own and learn in the process. I hope this forum and the experts who know this stuff can help me. More than the fixing the learning of the science excites me hence your help is much appreciated.
Pardon the length of the post. Wanted to get all info out there.