cartridge filter maintenence

[cscannon]

- I have a Pentair Clean and Clear Plus cartridge filter. The owners manual states the I should "introduce 3/4 pounds of DE per 100 spuare feet of filter area." However, in searching the forum, I haven't seen anyone else recommeding this. The manual states to do this "for first time operation on new pools". It is not clear to me if I must add more DE everytime I clean the filter or just when I replace the filters.

- A pool book that I bought recommends soaking the filter in dilute solution of trisodium phospate and muriatic acid. I am reluctant to do that as the owners manual says to just use plain water to wash off the cartridge. Besides which, it is not clear to me that any additional soaking is necessary.

- Finally, please indulge me in what might seem a stupid question. People say that their pool is crystal clear. My pool is too... until you turn on the light at night. Then the water seems full of particulate matter. Is this normal?

Thanks,

Steve

[waterbear]

- I have a Pentair Clean and Clear Plus cartridge filter. The owners manual states the I should "introduce 3/4 pounds of DE per 100 spuare feet of filter area." However, in searching the forum, I haven't seen anyone else recommeding this. The manual states to do this "for first time operation on new pools". It is not clear to me if I must add more DE everytime I clean the filter or just when I replace the filters.
My understanding is that is just the first time with the first cartridge to help remove any construction dust that might be in the water.
- A pool book that I bought recommends soaking the filter in dilute solution of trisodium phospate and muriatic acid. I am reluctant to do that as the owners manual says to just use plain water to wash off the cartridge. Besides which, it is not clear to me that any additional soaking is necessary.
Soaking is a good idea yearly. Use TSP or if that is not available in your area because of the phosphates (it's been banned im most states) then use an automatic dishwasher detergent powder like Cascade or Electrosol...they are mostly TSP. Use one cup for every 5 gallons of water. Do this before acid washing or any orgainics on the filter will harden into a cement like mass and you will need to replace the cart. Only acid wash if there are calcium deposits on the cart after soaking in TSP. Unicel, one of the largest manufacturers of OEM and replacement carts has these instructions for cleaning the carts
http://www.unicelfilters.com/pool_owners/ci_chlorine_users.asp
They also advice against using DE with carts but suggest that a cellulose DE replacement is ok to use.
- Finally, please indulge me in what might seem a stupid question. People say that their pool is crystal clear. My pool is too... until you turn on the light at night. Then the water seems full of particulate matter. Is this normal?
Carts filter to about 20 microns so you might notice some cloudiness with the lights on at night. Carts filter better than sand filters, which only filter to about 60 microns. If you want 'polished' water you need a DE filter which will filter to about 6 microns. IMHO, Carts are a good compromise between good filtration and ease of use/run time between cleanings!
Thanks,

Steve
Hope this helps.

[mas985]

I have been using Simple Green instead of TSP and it seems to work pretty well but I only soak the cartridges when spraying them off does not completely clean them. I have not needed to use acid yet.

[Simmons99]

My pool builder recommended using one of those jet hose nozzles (http://www.homeandbeyond.com/prod-0047041.html)- not the normal spray nozzle- in order to make sure that all the dirt is out of the folds. Also he recommended rincing this way at least once a week - he said waiting on the pressure gauge will only keep you from being able to completely clean out all the junk when you do clean it.

I've only had our pool for a little while - so this is just info I have gotten from him.

[waterbear]

My pool builder recommended using one of those jet hose nozzles (http://www.homeandbeyond.com/prod-0047041.html)- not the normal spray nozzle- in order to make sure that all the dirt is out of the folds. Also he recommended rincing this way at least once a week - he said waiting on the pressure gauge will only keep you from being able to completely clean out all the junk when you do clean it.

I've only had our pool for a little while - so this is just info I have gotten from him.
Your PB is giving you good advice. I hose off mine montly and use this to do it
http://www.sunpoolproducts.com/FilterCleaningWand.html
It has a pressure nozzle and also a brush nozzle with many small jets and a shut off valve where it attaches to the hose. really is a timesaver
My filter is oversized so it would take about a year for me to see any pressure rise but it is amazing how dirty it can get in a month. It only takes me about 10 minutes from start to finish to hose it off and that includes cleaning out the basket in my pump.

[SeanB.]

When I used to keep a fresh water aquarium, there was a product called Filter Aid that I used from time to time that was basically a very viscous solution that could be added to the sponge filter (1 drop per gallon, I think) to coagulate small particles. It removed even the smallest particles and gave you polished water in a very short amount of time.

I wonder if there is anything similar for pool filters and what the long term effect might be. It would be a short term fix, but might be nice to get the water really pristine for a party or something.

Anyone seen anything like this for pools?

EDIT: Did a little research on my own, and it looks like I'm talking about clarifiers. I'm going to have a cartrige filter, so may have need for something like this from time to time - any one better than the others?

[cwstnsko]

One thing to consider when you see very fine "particles" in front of the light at night is that if you have a SWCG, ozone, or any significant aeration, they are just as likely bubbles, not particles. Some times I turn my light on and things are perfectly clear, then the SWCG cycles and I get millions of little tiny hydrogren bubbles. You can't see them in the daytime, only at night with the light on.

[waterbear]

EDIT: Did a little research on my own, and it looks like I'm talking about clarifiers. I'm going to have a cartrige filter, so may have need for something like this from time to time - any one better than the others?
IMHO, clarifiers are not worth the money. If you want to improve the filtration of a cart you can use a cellulose based DE substitute. This will provide finer filtration without clogging the Reemay polyester filter material. Also, cleaning a cart too often will decrease your filtration somewhat. A slightly dirty filter will filter out finer particle than a clean one, whether the filter is sand, cart or DE. This is what you are actually doing when you add DE to a sand filter or DE substitute to a cart. You are making the filter medium 'dirty' and allowing it to trap smaller paritcles than it could when it's clean.
If you have a problem with your filter not keeping the pool clear perhaps giving it a longer pump run time will help so you get a bigger water turnover through the filter. Also, if you pump is a bit oversized for your filter that will lead to decreased filter perfomance.

[derrikm]

IMHO, clarifiers are not worth the money. If you want to improve the filtration of a cart you can use a cellulose based DE substitute. This will provide finer filtration without clogging the Reemay polyester filter material. Also, cleaning a cart too often will decrease your filtration somewhat. A slightly dirty filter will filter out finer particle than a clean one, whether the filter is sand, cart or DE. This is what you are actually doing when you add DE to a sand filter or DE substitute to a cart. You are making the filter medium 'dirty' and allowing it to trap smaller paritcles than it could when it's clean.
If you have a problem with your filter not keeping the pool clear perhaps giving it a longer pump run time will help so you get a bigger water turnover through the filter. Also, if you pump is a bit oversized for your filter that will lead to decreased filter perfomance.

Is the DE substitute available at most pool stores? Also, is there a rule of thumb as to how much to use? I assume it is based on filter area, right? My filter is a 100 sq ft, any ideas?