filter question

[corvairbob]

i have a sand filter and i have not had to back wash it since i change the sand 5 years ago. before that i would bw it about 3 times a summer. june july aug. the sand i got is #80 from pool supply.

[Watermom]

Do you have a specific question about this? Do you watch the pressure on your filter? What kind of filter do you have that only holds 80 lbs. of sand? What size pump do you have and what is the volume of your pool?

[corvairbob]

Do you have a specific question about this? Do you watch the pressure on your filter? What kind of filter do you have that only holds 80 lbs. of sand? What size pump do you have and what is the volume of your pool?

yes i do. i would like to know why the #80 grit sand will not filter my pool like the sand i used from the cement company. not 80# of sand number 80 sand. two bags so it may be 80# in there as well.

the filter is a swimquip model 14962 at 50 psi rating the pump is a stayrite 3/4 hp 110/230 re-connectible pump 1 1/2 in and out pool is 18 ft dia by 4 ft deep i figure 7600 gallons. when i have the sand you get in bags from the cement company used for mixing mortar it filtered the pool and about once a month i would back wash it. i then changed the sand and got it form the pool supply store and i have never had to backwash it since. i use the pre filter socks on the baskets then and now. just wondering if that would seem normal. my pool dets a little use and i run it 2 hours a day for filtering. i have to put in clarifier in the spring and it will last all season, till sept. thanks

[Watermom]

You are only supposed to use pool sand for a pool. Also, you should be running your pump 8-10 hours per day for adequate filtration.

[PoolDoc]

i have a sand filter and i have not had to back wash it since i change the sand 5 years ago. before that i would bw it about 3 times a summer.

There's a very simple rule that's a fundamental part of the BBB method: don't try to fix, what's not broken!

Is your water clear? If so, don't mess with your filter.

HOWEVER, for our sake, feel free. I have no idea how your filter could function that way. So if you do decide to investigate, I'd love to know what you find.

[PoolDoc]

oh yeah. membership updated.

[corvairbob]

You are only supposed to use pool sand for a pool. Also, you should be running your pump 8-10 hours per day for adequate filtration.

i have ran the pool for 8 hrs. 12 hrs. and all day and night it makes no difference. like someone said below if it's not broke don't fix it.

[corvairbob]

thanks for the answers. my pool is clean clear as long as i put in a cap full of clarifier every spring. no problems just asking if anyone else has this with their filters. i don't mind not having to backwash it and add water but i was just wondering why it's like this. i could have gotten the incorrect sand from the pool supply center. it happens. so if no one else has this with their filter then maybe i will just leave it be and enjoy the pool and summer. thanks

[PoolDoc]

Like I said, if it's not broken, don't fix it.

If, and when, you do a post-mortem on the filter, I'd be interested in photos of the internals, your set-up and macro-photographs (with a dime for scale) of the sand.

[Themadczar]

I had a pretty serious water issue when I opened this spring (first season as a pool owner)... While cleaning up the pool my filter would gain pressure and I would backwash as is normal. Since I resolved the water issue, my pressure has not increased at all. My pool is clear and all is well. I have backwashed once or twice even though the pressure had not increased just to make sure it was clean. From what I understand there is no harm in backwashing "too much". In other words, you cannot backwash too much. Also I plan to add a small amount of de to my sand filter (search other threads on the forum if you are curious about it) in order to 1) make sure my sand isn't channeling, and 2) enhance the filtration. I have also read about washing the sand with a hose, but I am not planning to tackle that until the end of the season. None of this really answers your question, but it does give you some other areas to explore.

[PoolDoc]

I have backwashed once or twice even though the pressure had not increased just to make sure it was clean. From what I understand there is no harm in backwashing "too much".

Not actually correct.

With sand filters, the dirt tends to become part of the filter media. As a result, the filter removes finer and finer particles, as the cycle continues. This is particularly important during algae cleanup.

On the other hand, sand in filters that are rarely or never cleaned can become 'goo-ey'.

A better solution, rather than excessive backwashing, is adding your chlorine via the skimmer. This will break down the oils and goo, that may otherwise accumulate. Just be SURE that there is no MIXING of chemicals going on -- do NOT pour bleach into a skimmer that has a chlorine tab in it.

And particularly, do not dump cal hypo granules in, if you have added stabilizer to the skimmer in the last 3 - 4 days.

[Themadczar]

So are you saying that I should only backwash when the pressure guage is +5 psi even if it's been weeks (or it never happens)?
Thanks for the clarification though. I learn something every day here!

[PoolDoc]

Yep. That's what I'm saying.

If you want to add DE to polish your water, you can probably force a backwash, after the really fine stuff is removed.