Pump/Filter Too Large - Is It Possible?


LifeTime Supporter
Jul 24, 2007
Lafayette, IN
Hi All!

Another newbie here, although I feel I've learned alot already, just browsing thru the posts. Anyway, I'm wondering if such a thing as over-filtering is a possibility. It seems unlikely, but what better place to ask?

For background, we bought and installed an Intex metal leg kiddie pool. It's 16' x 48" so it holds around 5000 gallons. The pump that comes with these pools is rated at 800 gph. I was thinking of buying a more powerful (or higher flow rate) pump, when by brother offered to give me his older sand filter/pump combo.

It is only a few years old, so I gladly accepted. (He has a much larger above ground pool.)

So I'm using the used sand filter/pump combo now. The pump is 1.5 hp (I don't have any flow specs, but it is a Hayward) and the sand filter holds 250 lbs of sand, and says it's a "high flow rate" model.

We've had the pool up for a little over a week, and everything seems great so far. But I guess I'm wondering if turning over the water so frequently (I usually run the pump for 4 hours at night, and another 4 during the day) could cause any negatives, such as helping the chlorine to leave the water faster, things like that.

I'm not so worried about the electrical usage, as long as I keep the water nice and clear. In the Clint Eastwood western Unforgiven, there's a scene where one guy is loading up several guns before an anticipated shootout - when asked about it, he says "I don't want to die for a lack of shooting back" - that's kind of what my thinking is right now on filtering the water!

You should be fine with the pump and filter. It will work MUCH better than the one that came with your pool!


TFP Expert
LifeTime Supporter
Mar 29, 2007
Coastalish 'down easter'
Steve, welcome here! :-D You've made a great choice in coming here to learn about and how to take care of your new investment!!

Pump sizes vs. filter sizes aren't quite my 'ballywick', but I can tell you that a larger filter and a smaller pump will give you better filter performance. Your new 1.5 HP pump and 250 lb sand filter sounds like the pump is a bit big for the filter :( What was the original pump? - if it was a 1 HP or 3/4 HP, you might want to think about using the original pump with the new filter.
In any pool, you want to maximize the filter while keeping the pump just big enough to provide sufficient circulation/ turn over.
I'm hoping that one of the folks that really know this stuff will 'chime in' and be able to give you some 'hard' numbers on flow rates, etc.
I feel that every new poster should have their question answered quickly, even if I can't give the complete answer -
Welcome and we will help you with your pool!!


LifeTime Supporter
Jul 24, 2007
Lafayette, IN
Thanks for the quick feedback.

Waste, you were asking about the pump and filter combo. As far as I know, this is the original combination of pump/filter that my brother bought 3 or 4 years ago. Maybe the salesman at the time sold him more pump than he needed!

I put new sand in it, and it runs at a steady 10 psi. Any recommendation on what number I hit should trigger me to do a backwash? (The only bad thing about used equipment - no manuals)

I'll see how it goes this year at least. When it's time to get a new pump, it's good to know I can get one that's a little smaller.


LifeTime Supporter
Jul 24, 2007
Chicago, IL

I had a very similar experience to yours. I put up a 15' Intex EasySet this year and soon realized that I needed to run the prepackaged pump/filter 24/7 to keep the pool water clear. I also needed to hose off the filter every other day and change it once a week. The other problem with the Intex pump is that it doesn't give you enough suction to vacuum properly. I was soon ready for something else.

I found a used (one year old) Hayward 1HP Pump/DE filter combo on Craigslist for $200. It's a bit of an overkill for our small pool, but I figured I would be ready for when we upgrade to the full AG pool in the next year or two.

I've had the Hayward unit running for about 6 weeks now. Between running that about 6 hours a night, following the BBB protocol, and checking my water nightly, I haven't had any problems. :lol:

Good luck with your setup. It's sounds like you made a move for the better.


Mod Squad
TFP Expert
Platinum Supporter
LifeTime Supporter
In The Industry
Apr 1, 2007
Sebring, Florida
Hi, Steve,


Re: backwashing pressure. I think it makes sense to look for something around a 50% increase in filter pressure and then backwash. So if your normal is 10, then 15 is a backwash signal. I certainly wouldn't want filter pressure to double and a 10-20% increase would seem pretty insignificant.


Well-known member
Jun 25, 2007
I learned the same lesson, have an Intex"eliptical" Pool 18X48X52 with Hayward 22" sand filter( DE added) and 1HP pump. It keeps it ALOT cleaner tha n the pump/filter( joke) combo that came with the pool 2 years ago. The only problem I had was getting the fittings to work, took lots of silicone....On a positive side, i can run my pump/filter for 6 hours a day, have a complete turnover, and leave it till the next. Saves on the electric bill!

My pool is twice the size of yours, and your filter is a little bigger, so it should be all good.


LifeTime Supporter
Jul 24, 2007
Lafayette, IN
Duraleigh, thanks for the advice. I haven't seen any deviation in pressure yet, but 1 week isn't very long. The pool's not near any trees or large plants, so it looks like the only thing visible being filtered is bugs.

Edbson, you mentioned adding DE to your filter. I've seen a couple of posts on that topic, and I know it's basically some type of fossilized remains of some organisms. I guess my question would be, how important is it? Given the filter capacity I have vs. pool size, is DE something I should consider adding? And if so, does it need to be mixed with the sand before I put it in the filter (I've obviously already added the sand) or can it be used to "top off" the sand? And finally, how much would I need to add - based on pool size or filter size,and where do I find it? Whew - a simple question seemed to grow into 3 or 4 real quick!

Thanks to everyone else who responded as well - this is obviously a well used and friendly forum! I'm not just a newbie to the forum, but to pool ownership as well - I already feel I'm on the right path for clear water success


TFP Expert
Platinum Supporter
LifeTime Supporter
May 7, 2007
Silver Spring, MD
Added DE allows the sand filter to filter finer particles than it is able to filter without the DE. The improvement is not as large as from using a DE filter, but it is noticable, particuarly with older sand. The sharp edges get worn off of sand over time, causing it to allow larger and larger (but not actually very large) particles through as it gets older.

Adding DE to a sand filter is done after each time you backwash. To find out how much DE you should use you need to add it very slowly, say 1/4 cup every two or three minutes, repeating until the filter pressure has gone up 1 psi after the two or three minute wait. From then on you can add that amount all at once each time.