Moving from Cartridge to DE, what system to use?

[linen]

Right now I have the Hayward star-clear c500, 50sq ft. which should handle our 7500 gallons with no problem.

Handle yes, but the tfp recommendation would be a 112 sq. ft. cart for your pool, and that would reduce the frequency of cleanings needed.

How often are you having to clean?
What is the clean filter pressure?
At what pressure do you switch filters?
Is one of your filters "better" than the other?

I'm with Robbie on this one, my sand filter gives me crystal clear water...so I would guess something else is going on here.

 

[RobbieH]

Linen, Dave nailed it. His filter is too small for the pump he has!

 

[linen]

Linen, Dave nailed it. His filter is too small for the pump he has!

I take no credit, bama and you had it nailed before I meddled.

As for the sizing, I can't take credit there either...I was just sizing the filter using mas985 recommendations in: http://www.troublefreepool.com/hydraulics-101-have-you-lost-your-head-t915.html#p6543

 

[rwrogers11]

Cool, I'll look and see what I can find in the 100sq ft.

 

[JasonLion]

That is the correct cleaning technique, though I would only do the acid bath if there is some indication of calcium scaling problems.

 

[rwrogers11]

My filters are both Hayward filters, the dealer gave me two when I bought the system.

The clean pressure is about 13psi, by the time I swap them they are up to about 22psi.
I'm having to rinse them every other day and clean them every weekend.

 

[linen]

Cool, I'll look and see what I can find in the 100sq ft.

For cartridge filters you can't go too big, though 100 will be adequate.

 

[linen]

The clean pressure is about 13psi, by the time I swap them they are up to about 22psi.
I'm having to rinse them every other day and clean them every weekend.

I believe when pumps are correctly sized to cart filters, the pressure tends to run much lower than 13 psi (more like 3-4 I think), so this backs up our concerns about your pump size.

Our recommendation on here is to clean the filter when the psi rises 25%, so I think you are waiting to long and that is part of the problem. Even with a small filter like you have, that cleaning frequency seems to high to me. Are you getting a lot of junk and organics in your pool?

 

[rwrogers11]

No, just particulate. I think the overpressure and a few times that I did have alge blooms, may have damaged the filters so now its not filtering, just blowing past.

 

[rwrogers11]

I'm also using 1 1/2" plumbing for a total run of about 20', is there an issue with that?

 

[Bama Rambler]

That size plumbing is fine. I wouldn't go to the trouble of replacing it. At that short distance you wouldn't gain much by upping it to 2".

 

[rwrogers11]

Cool, well thanks for everyones help and input. Now I just have to see which is better, smaller pump or larger filter. I'm always one for going bigger, hence the 1HP pump, but I'll have to see on the cost difference.

 

[linen]

Cool, well thanks for everyones help and input. Now I just have to see which is better, smaller pump or larger filter. I'm always one for going bigger, hence the 1HP pump, but I'll have to see on the cost difference.

Big pumps are almost always a bad idea, unless some water feature requires it...but big filters...especially carts are generally a good idea (backwash requirements on sand filters limit how big you can go for a given pump).

With that said, your pump is not monstrously big so I would focus on finding a more appropriate filter size.

 

[rwrogers11]

So last question. If I have to spend money, is it better to go larger filter or smaller pump. It looks about even on the cost, or at least very close.

 

[rwrogers11]

Thanks Linen, I'll get a larger filter, looking at the Hayward C1200, but I'm going to look and see what other brands are out there as well.