Going from sand to DE, anything I should know?

[pisymbol]

This year I decided to replace our 18 year old sand filter (came with the house when it was built in '97) with a Pentair DE one. I did so after a lot of online research and just the general notion that DE cleans better than sand.

I was wondering if anyone has also gone through this process and if there are any tips or issues I should be aware of. Please keep in mind that this is my 2nd year of pool ownership so I consider myself still a beginner.

When I had sand last year, I just backwashed it every 2-3 weeks and that's about it. I'm told for DE you have to clean the filter once a week (maybe 2 depending on usage).

 

[mikech]

Backwashing obviously depends on quality of water going through a DE filter, but typically shouldn't be more than once every 3-4 weeks, and a deep clean of the grids 2 or 3 times a year.

The only other consideration is that DE 'dust' should not be inhaled so take care in handling, and is is not bio-degradable so take care where you backwash (check local regs if it can go down sewer drain). If either of these bother you, then a switch to cellulose rather than DE as the filter media may be a consideration (though expect more frequent backwashing and cleaning).

Mike

 

[kcindc]

I love my DE filter. How often you backwash is variable, depending on the size of your DE filter vs the size of your pool, usage, keeping your FC at optimal levels, etc. You should deep clean the filter each year when you close the pool.

That being said, you backwash when your pressure rises 25% above your clean pressure. The amount of DE at startup is more than the amount you add after you backwash. When you add DE, make sure to split the amount in batches a minute or so apart. I make sure that the skimmer runs clear before adding the next batch. You can clog the lines if you add it all at once.

I suggest reading these tutorials:
Pool School - Maintenance and Cleaning of Pool Filters
DE Filter Cleaning Tutorial

 

[pisymbol]

How much DE do you add to the skimmer after you backwash? I was told like 8lbs or 8 scoops. Not sure. I have two 10 pound bags right now

 

[mikech]

80% of the manufacturers recommended amount on first install or deep clean

 

[pisymbol]

Got it. Do you guys ever use Rinse on your multi-port valve? The manual for my Pentair just says turn it to BACKWASH, let it go, then turn it back to FILER and dump DE in the skimmer so it replenishes. Is that right?

 

[kcindc]

Yes, you should use the RINSE after every "BACKWASH" setting. It moves water in a similar way as filter mode except the water goes to waste instead of going back to the pool. It does two things: a) keeps dirty water from going back to the pool, b) changes up water movement to increase the efficiency of next backwash.

Here are my normal steps:
Backwash until clear water in the sight glass
rinse 15 seconds
backwash until clear water in the sight glass
rinse 15 seconds
set to filter

If I have a really dirty filter (like waiting too long to backwash), I'll add another cycle:
Here are my normal steps:
Backwash until clear water in the sight glass
rinse 15 seconds
backwash until clear water in the sight glass
rinse 15 seconds
backwash until clear water in the sight glass
rinse 15 seconds
set to filter

 

[pisymbol]

Thanks kcindc. Much appreciated it.

Well, the only thing that has me a little intimated is a deep clean (tearing off the top and hosing down the grids). How often do you do that?

 

[kcindc]

You deep clean once a year and you do it when you close the pool for winter. I've done it twice, but I swear I'm not doing it again this winter. My mid-aged, female arms and hands have said no more!

It isn't difficult or complicated, but it is dirty and wet. It is scary the first time, but there really isn't anything to be scared of... just make sure you've released the pressure before you open up the filter. The most difficult part for my aging hands is getting the bottom drain plug on and off.

My pool company deep cleans the filter as part of the normal closing process, so if you have a company close the pool for you, you won't ever have to worry about it.

 

[pisymbol]

You deep clean once a year and you do it when you close the pool for winter. I've done it twice, but I swear I'm not doing it again this winter. My mid-aged, female arms and hands have said no more!

It isn't difficult or complicated, but it is dirty and wet. It is scary the first time, but there really isn't anything to be scared of... just make sure you've released the pressure before you open up the filter. The most difficult part for my aging hands is getting the bottom drain plug on and off.

My pool company deep cleans the filter as part of the normal closing process, so if you have a company close the pool for you, you won't ever have to worry about it.

Got it! Thanks kcindc. Much appreciated.

 

[BlueWave8]

Even another perspective if you'd like....I have an indoor pool, so my filter doesn't get nearly as dirty as most I'm sure, but I'm OCD and I can't stand the idea of backwashing and not knowing how much DE (if any) is left on the grids.

So I never backwash, except when I am about to break the filter down for deep clean (which I do once a year). Only then to I backwash to get whatever will come off the grids off, then turn off the pump and break the system down for a deep clean. Then I put the full amount in and start everything back up.

I will add that I (personally) am not crazy about deep cleaning. I don't think its hard or difficult at all, its just messy and tedious. And then there is DE all over my patio weeks...or longer. That's why I'm going to go with a cartridge filter for my next pool, but that just depends on what you like. I'm sure I'll miss how clear my water looks at night with DE.

 

[pisymbol]

Even another perspective if you'd like....I have an indoor pool, so my filter doesn't get nearly as dirty as most I'm sure, but I'm OCD and I can't stand the idea of backwashing and not knowing how much DE (if any) is left on the grids.

So I never backwash, except when I am about to break the filter down for deep clean (which I do once a year). Only then to I backwash to get whatever will come off the grids off, then turn off the pump and break the system down for a deep clean. Then I put the full amount in and start everything back up.

I will add that I (personally) am not crazy about deep cleaning. I don't think its hard or difficult at all, its just messy and tedious. And then there is DE all over my patio weeks...or longer. That's why I'm going to go with a cartridge filter for my next pool, but that just depends on what you like. I'm sure I'll miss how clear my water looks at night with DE.

I hear ya! This is my first full year with the pool and a new DE filter. Other than opening, I'm told backwashing is pretty rare with DE (once or twice a season).