Cartridge vs. DE

[yossarian]

I've read some posts about this and wanted to ask in light of our situation. We live in CT and have a swimming season that goes from mid-May to October (at most). We have a 33,000 sf pool and are currently running a Jandy CL580, which is about as large a cartridge filter as we can get. I have gotten used to the cartridge filters, but grew up with a pool that had a DE filter.

I find that the cartridge filters are an incredible pain to deal with when the pool is first opened as they do not trap dead algae very well, and they get dirty very quickly. I have started using skimmer socks, which is a big help, but they get clogged up quickly as well. For me to clean the cartridges, it is a pretty big production, from opening the filter, removing the cartridges, hosing them down and replacing them. I do keep spares on hand, but this is still pretty time-consuming. Plus, a set of spares is not cheap -- about $200. The skimmer socks have made it possible for me to get by with 2-3 cartridge cleanings within the first month of opening, and one more cleaning toward the end of the season.

My understanding is that a DE filter will do a better job of filtering out dead algae. Of course it needs to be backwashed. I am sure DE filters have changed over the years, but I recall cleaning out the fingers and replenishing DE as part of the backwash and cleaning process (it's been over 25 years). It took some time, but it was nowhere near as time-consuming as cleaning the cartridges. Plus, I recall the filter disassembly being much easier with the DE filter than with the cartridge system.

One concern I have with the DE system is that we have a well, and it is pretty easy to tax the pump and "water treatment plant" we have in our basement. Is the water loss with DE backwashing significant, or is it something that can be dealt with by allowing Mother Nature to handle some of the work? After all, when I clean the cartridges, we are taking water out of the pool as well, even if it is only 100 gallons or so. I find myself letting water out of the pool throughout the Spring and Summer as the rains add quite a bit of water.

I believe that our filter is about 20 years old, so I am assuming a replacement is on the horizon. When I consider that a spare set of cartridges is about 20% of the cost of a filter, it seems like a DE system makes more sense for us.

 

[mas985]

Does your setup currently have a bypass around the filter as well as a vacuum to waste? This is the only way I would use a cartridge filter on pool that closes for the winter. With this configuration, you can bypass the filter when killing the algae and then vacuum to waste to remove the algae so basically, the cartridge filter is not used at all during the opening process.

The issue I have with DE filters, as you have pointed out, they should be broken down and cleaned one a year. That is my current cleaning schedule for my cartridge so I really don't see a maintenance difference between DE and cartridge IF the cartridge is large enough to get away with once a year cleaning.

But for opening a pool, a sand filter is probably the easiest and if you ever need the cleaning ability of a DE filter, you can always add DE to the filter.

 

[yossarian]

No bypass filter, so no way to vacuum to waste. When we opened our pool the first time, the pool service was telling me to vacuum to waste. I explained that was not an option. My solution was to buy a small vacuum with its own bag and use that to remove some dead algae. Between that and the skimmer socks, I get much of it. But it takes a long time and quite a bit of work.

Is cleaning a DE filter about the same time-wise as cleaning a cartridge filter? It sounds like a DE filter can get cleaned less often where we are, particularly if I can vacuum to waste.

 

[jblizzle]

Cleaning/backwashing a DE filter is a pretty messy job, depending on where you have available to you to drain the water to.

Any filter type can go longer between cleanings if you get a larger size.

It is easy to add a waste option to a cartridge filter setup ... just add a 3-way valve between the pump and the filter.

 

[yossarian]

Draining water is not an issue for us. My issue is that we have as large a filter as possible I believe. Maybe a waste option is worth pursuing, although I do expect our filter to **** out at some point, although I guess there really are not many parts to go bad.

 

[jblizzle]

You are right, your cartridge filter is big. I do not think you would have fewer cleanings with a DE filter. A big sand filter would be easier to keep clean, at the cost of a lot of backwashed water.

You really should not be having to clean that filter very often. I would expect 1-3 times per year. If it is more than that, then perhaps there is a chemistry issue that should be corrected.

 

[Bama Rambler]

Since you stated that you're on a well, and that you can tax the system, I'd stick with a cartridge filter, and spend my time and effort in reading and learning the best way to close your pool so you open to clear water next year. That way you don't have to clean the filter but once a year. therend'll be no more need for many cleanings when opening.

Both sand and DE filters waste lots of water, So being on a well is a concern.

 

[duraleigh]

I find that the cartridge filters are an incredible pain to deal with when the pool is first opened as they do not trap dead algae very well, and they get dirty very quickly.

This answer does not address the question you asked but it addresses the problem.

There is somewhere around a 98% chance that your problem is not with the filter but rather your water chemistry. Cartridge, DE and Sand are all perfectly capable of giving you a crystal clear pool but only if your chemistry is correct.

We see this VERY often on the forum. You clean the filter and put it back in. However, there was inadequate chlorine in the pool so algae, even though you couldn't see it, began to grow.

Then you chlorinate and kill the algae and the dead algae falls to the floor. What dead algae stays suspended in your pool water, quickly clogs the filter and the cycle repeats itself.

The prevention for this is precise testing and keeping your FC levels high enough to keep algae out of your pool but low enough not to do any damage.

Posting a complete set of test results is the beginning.

 

[jmhjgh]

I am in Minnesota so our swimming season is similar to yours. We keep our pool covered when not in use, which helps limit how hard the filters have to work. We have cartridges, and if we stay on top of our water chemistry, then we only clean the filters at the end of the season when we are winterizing. Your filter is large and should not need more than 1-2 cleanings a summer.