sta rite system 3 cardtidge as good as de?

[waterbear]

Evan,

I swore I would never get involved in this interminable (and redundant)argument but you have misspoken.

You "clean" a sand filter by backwashing....no further "cleaning" is necessary. It is misleading to inexperienced people to imply that carts have a lower maintenance load.

I have to disagree. To 'clean' a sand filter requires breaking it down, flushing the sand with a hose to unclump it and get rid of any channeling that has occurred, and possibly using a sand cleaner if there is much scale clumping the sand together. IMHO, this should be a yearly procedure (and is similar to a yearly soaking of a cartridge in TSP or dishwater detergent). Backwashing just removes the excess dirt from the filter that usually just sits on the top layer of the sand. Channeling DOES occur in a sand filter and it lowers the filtering ability. Backwashing does not eliminate channeling. Backwashing is certanly an easier procedure than hosing a cart off....these would be equivalent processes...but to really clean any type of filter requres a filter breakdown and here the cart is definately easier, IMHO!

[Poconos]

Evan,
I don't know where you're getting your information as it is incomplete and contrary to almost everything that has been posted about sand filters in the past. First, channeling will occur with an oversized pump. Why don't you state that? When the pump and filter are properly sized this is not an issue. Next, backwashing will break up any clumps on the surface unless something has gotten into the filter to goo it up, like baquagoo. Next, sand doesn't have to be routinely 'cleaned', again, unless something has gotten into it to cause problems. Finally, for 9 seasons I never had a problem and the only time I dumped the sand was to make a unique addition to let me drain it better for winterizing. And I put the same sand back. Never added, never changed, never got my hands messy.
Now...I'm tempted to exercise my power as a moderator and lock this thread but I won't. Not yet. It has gotten completely off topic and as Dave said, is misleading to inexperienced people. Enough of this sand filter nonsense and misinformation. Guess I'm just a little rattled right now.
Al

[waterbear]

You might want to consider moving it to the china shop then. Channeling can occur even in a free flow sand filter that is not pressurized. It is the nature of the beast when filtering with sand. Organics, oils, and scale can collect on the sand and backwashing will not effectively remove them and over time they will take their toll. These same organics, oils, and scale also cause DE to clump and bridge and are what effectively 'wears out' a cartridge. It is true that a pump that is oversized can cause channeling and other problems but that is not the only reason it occurs. Cleaning the sand and declumping it is not the same as replacing the sand. All filter mediums get dirty with use and a dirty filter medium reaches a point where it is just not as effeicint anymore.

[coryinsocal]

thanks alot for helpfull (on topic) replies. i think i'd also prefer the de, so i may just do the teardown instead of backwashing when needed. it shouldn't be too often as the 36 sq ft is pretty oversized for my pool. as a side note, i've since found out that long beach,ca doesn't even allow backwashing of DE to the sewers without a separator anyway. only sand can be backwashed to the sewer without treatment.i figure i can get by with the breakdown method till i'm forced to buy a separator.... does anyone forsee any major problems with a plan like this?

on this note, since the separator is just a second trap, is there any reason to spend alot on one? should i just try to go cheap? also, i heard that adding a separator can decrease the backwash effectiveness due to gpm limiting characteristics...

[JohnInSoCal]

I guess this is kind of like a religous debate or coke/pepsi but I'll throw in my .02 I have tried both modern DE and cartridge systems and prefer the DE. I suppose a small cartridge may be easier to deal with than a DE filter but the 4 cartridge large sq/ft hayward is a big pain to clean and takes several hours if you want to clean it well. Sure you can take it out and give it a quick squirt and throw it back in the filter and consider that a cleaning job. But dirt/grime really gets into all those little pleats and it seems to take forever to clean those.

After 1 year with my 4 cartridge hayward I decided to switch to DE because I figured DE couldn't be any harder than the darn cartridge to clean and to replace 4 cartridges costs a small fortune, almost as much as a new filter. I was amazed at the clarity difference it made as well. Perhaps my cartridges were just bad but they were not even 1 year old, but the DE made the water really sparkle. And at night you can definately tell a difference by looking in front of the light.

Because my DE system had a problem I ended up tearing the system down a couple times to find a hole and didn't find it very difficult at all, it was faster than a full clean of 4 cartridges. So I am definately sold on DE over cartridge. I can't say anything about sand as I have never tried it.

-- john

[coryinsocal]

i gues now i'm looking into separation tanks (which should maybe be another thread). in addition to the innefficiency during backwash question above, does anyone here have experience using one where you return the separated water to the pool? most manufacturers say that you can do this, but it seems to me, that unless the tank filters as well as a de filter, you'd get a buch of crud making it past the sep tank and back into the pool. does anyone have any experience with this?

[waterbear]

IMHO (and this will probably start another debate!), DE filters should be broken down and cleaned, not backwashed. My reasons are as follows:
1. when you back wash you really don't know how much DE has washed out so you really don't know how much DE to replace...too little and you will not have good filtraton...too much and you might get bridging between the grids (and if you have ever had to pick away at rock hard DE stuck between the grids you understand what I mean!)
2. Backwashing forces water backwards through the grids....If you run a DE filter without DE, even for a short time, you run the risk of dirt clogging the grids and the grids getting coated with oils and organics. You then have to break the filter down and clean the grids...when you backwash you are still forcing dirty water through the grids (backwards) and the same thing can occur.

As far as "bumping' a DE filter....knocking the DE off the grids so the dirt can mix with it and then recoating the grids is not a good idea, IMHO. Dirty DE is dirty DE!

Just my 2 cents!