Is water bypassing the cartridge in my new Jandy CS150 filter?

[eviscito]

I recently self-installed a new Jandy CS150 for my 20,000 gallon in-ground pool. I have a 3/4 HP pump. Although I'm not a plumber, I understand the basics of flow, pressure, air leaks, and so on, and I think that the installation went 99% well. With the pump running, the water flow into the pool is very good.

After 2+ days of continuous filtering (in a very green pool to start with), the water is still pale greenish cloudy such that I cannot see the bottom. I've shocked and waited 18+ hours three times. When I pulled the cartridge out for cleaning, the first two times, it was full of algae and other organic matter, and I cleaned it off with a hose.

There are two anomalies that disturb me. First, the pressure has never gone above 0. I expect it to run at low pressure, but is not actually pegged to the 0 bar. There seems to be a small amount of air leak somewhere prior to the pump ingress, since after a n hour, I can bleed more air out of the filter using the top air release value. I don't think this small amount of air leakage would reduce pressure to 0, especially given the flow I feel when I put my hand in front of the wter return in the pool.

Second, when vacuuming, I witness a couple of very green algae plumes going back into the pool. This means significant water must be bypassing the filter element. I was told that there could be a rip in the paper, or missing parts that should go around the cartridge. I have two cartridges, one of which came with the new filter, and neither came with any extra parts, nor does the installation manual mention needing any, so I kind of rule that out. I'm currently using the second cartridge for the last 12 hours, and haven't yet vacuumed, so not sure if a big plume will form using it, but the water is still foggy as summer in San Francisco.

Any idea how I can troubleshoot the water bypass problem and/or the 0 pressure problem?

Thanks!

 

[JohnT]

Welcome to TFP!

Green water is a chemistry issue, so you need to treat that along with figuring out what is happening with your filter.

Shocking and waiting 18 hours is just going to annoy the algae. You need to raise the chlorine to shock level and then stay on it by testing and adjusting as often as every hour. Read up on SLAMing Your Pool and Defeating Algae

What does the water in your pump strainer basket look like when the pump is running? It should be clear and difficult to even tell water is flowing. Bubbles or surging and splashing water indicate an air leak. The strainer basket lid is among the most common sources of an air leak, so make sure the O-ring is in good shape, lubricated with pool lube and that the lid is tight. The article on Suction Side Air Leaks may help you narrow it down.

 

[eviscito]

Thanks for the quick reply. I'll test the water and adjust the chemistry. I'll read the sections you mention on SLAM and algae, and respond accordingly. As for the water in the pump strainer, there is some air in there, but as it has cavities above the level of the egress, I thought that would be true even without air leaks. Nonetheless, I'll relube the ring, which is relatively new, and read the section of air leaks.

 

[eviscito]

Update:

Checked pump cage gasket area. There are bubbles there. I recleaned and lubed the gasket and both top and bottom surfaces that contact it. Still a few bubbles lurking in there. Later, when I have more time, I'll check the other joints on the supply side.

Tested water, free chlorine was non-existent. Re-shocked and will monitor level hourly. pH looks reasonable, hardness look reasonable.

Water flow is very good, and pressure on my hand at the outlet into the pool is high.