Does this extrapolation sound reasonable...

[lapzanpool]

As I've posted elsewhere, I'm now into week 4 of cleaning my pool. I think the algae is dead (or most of it) but there is so much suspended debris that it is taking forever to clean the pool. I also had some air leaks on the suction side, so for the first 3 weeks, the pump\filter was not operating at optimum efficiency. In the last week I fixed the air leak and I'm cleaning the filter 2-3 times a day (Sta Rite 450 sq/in cart). Progress is finally being made. The water is still extremely cloudy but I can finally see the third step (and a brick that is in the shallow end. I bounced it off m head in frustration, hoping I'd be knocked out and fall into the pool, but no such luck).

That said, this is about as slow as I've ever seen the pool clear. So slow, I started to think maybe my filter carts are shot. So, I decided to just filter my spa. It is about 350 gallons. It took about 4 hours to get is reasonably clean. My pool is 50,000 gallons. If I do the math, and if the filtration rate is linear, that works out to about 570 hours to get the main pool clean. Please "say it ain't so". If that is the case, then that puts me into September before this thingis clean and I might as well bag it.

I'm going to do some vacuuming to waste, so that should help but this filtration rate is way too slow. Perhaps I do need new filter carts after all. I suspect the filter may be letting too much finer stuff through and that is why it is taking so long to clean this thing.

So, is my extrapolation on the money? If it is, time to fish out that brick from the shallow end and try again...

 

[JasonLion]

The filtration rate is not linear. It won't take months to clear the pool, but it is going to take a while.

If you are in a hurry you could try a floc treatment. Floc requires being able to vacuum to waste, and is a fair bit of work, but it can clear up a pool in 24 hours.

 

[frustratedpoolmom]

I think the algae is dead (or most of it) ...

Is your FC holding overnight?

 

[lapzanpool]

I believe it is. I ran out of reagent, so I cannot get an accurate reading. Prior to running out of reagent I go to a drop of about 1 ppm overnight. I'm wondering if my cartridge may not be filtering well. It is about 5 years old. I had an older one, 7 years, that I used when I initially opened the pool. However, with that filter the pressure never go above 20 PSI, even after using a clarifier. That is unlike an behavior I ever saw in the past. This filter will go down to 20 PSI after I rinse them off and climb up to 30 PSI after a few hours.

As I said, I'm cleaning the filter 2-3 times a day. If I don't clean it that frequently, the flow rate drops very low. I'm about to pull the trigger on trying some floc so I can at least remove a substantial amount of suspended matter. The filter just doesn't seem to be able to keep up.

I've been keeping the FC up at about 18, have a CYA of 40. The water is grayish cloudy. I just looks like a lot of dirt suspended in the water.