What filter to buy - advice?


New member
Jun 5, 2010
Hi everyone... I know you guys just responded to a similar question by another new member, but I'm hoping you have the time to give me some advice. My setup is not very complicated, but I'm completely new to pools so I'm not sure what to do. I'm looking for a new filter--I want to upgrade my large sand filter to a cartridge filter. I'm not sure what size to get.

I also want an automatic chlorine feeder, but I guess that's beside the point. I'll take any recommendations on that though, if you have any.

My pool is an odd shape, but I tried to measure and calculate the capacity and surface area the best I could. Here's what I have: about 380 square feet, average depth of 5.5ft (3-8 range), and that comes out to about 16000 gallons or 2095ft^3.

From what I've read, I should be looking for about a 8-10 hour turn over, which would require a flow of about 32.7 GPM. I've also read a disired flow of 50GPM would be appropriate, but I really have no idea. I'm even more confused about GPM and relation to cartridge filters sq ft specifications. My pump is fairly new and is 1HP. Pics below.

I'm considering a Hayward Star Clear Plus either C900 or C1200. Any advice? Are either appropriate?


Bama Rambler

Mod Squad
TFP Expert
Bronze Supporter
LifeTime Supporter
Jun 22, 2009
SouthWest Alabama
I'd opt for the C1200 or larger. You won't be sorry going with a larger filter but you will wish you had gone bigger if you get one too small.

Johnny B

LifeTime Supporter
Mar 19, 2009
Charlotte, NC
FWIW, I don't know much about a cartridge filter but it seems like the labor of it is more like a DE filter which I know plenty about, I like my sand filter much better- far less work.


New member
Jun 5, 2010
The sand filter I have now has been horrible for me... Maybe I'm doing something wrong with my maintenance, it's possible.

First, it doesn't seem to filter effectively. From what I understand the cartridge filters get down to 10 microns. The DE does better, but I heard they are harder to maintain.

How often am I looking at cleaning a cartridge filter? I'm backwashing my sand filter probably once a week to prevent it from re-circulating whatever it is gathering that week. That dumps a lot of water out of my pool. I think the valve on the filter is going too, as when I have it on waste (say, when I vacuum) it sometimes starts shooting the Crud out of the jets. Obviously making everything cloudy and throwing the trash right back in.


TFP Expert
Platinum Supporter
LifeTime Supporter
May 7, 2007
Silver Spring, MD
Far more important than the sand/cartridge/DE choice is the size of the filter. You will be much happier with a larger filter of any kind than you are with your current filter. Builders and standardized kits tend to use undersized filters to save money. Getting a larger than required filter means much less frequent cleaning/backwashing of the filter and better filtering overall.

Each kind of filter has advantages and disadvantages, but everything you have mentioned is because your filter is too small, not because it is a sand filter.


I'm a cartridge filter guy, and always have been. I like the Pentair Clean and Clear Plus 420, and I have a StaRite Mod Media 450 on my pool. Both are great filters, with tons of surface area and dirt retention availability. They are both very easy to clean (I do mine every 6 months, if they need ti or not!) and do a great job of keeping the pool clean.

As for chlorine introduction to your pool, I like the Liquidator and use it on my pool. I've had all of the other types of feeders (erosion, SWCG, Dichlor feeders) and I found the Liquidator to be the easiest and simplest of them all (you can check my sig for more info, if you like). I dump bleach in mine once or twice week and check it a couple times just to make sure it is doing its thing! Doesn't get much easier than that!


LifeTime Supporter
May 11, 2012
I have a 29000 gallon pool, ecopump 2 speed pump with a hayward 500 lb sand filter with ZEO. I am dumping the ZEO and going for the Hayward recomended filter sand. Should I just dump the sand filter and switch to a Hayward C1200 cart unit so I dont keep having stuff thru the sand filter? This is a new inground vinyl liner pool. I use a salt water system. I went with a large sand filter so I would have a nice clean pool. The fool and the pool store talked me into ZEO. SO I am now a Pool School student. should I just keep the monster sand filter I have with sand and see how that goes or get a big cart unit with 2" lines, thanks for your advice.