I will NEVER backwash/recharge my DE filter again...

[Austintatious]

For several reasons I had come to believe that back-washing then recharging my DE filter was a bad idea. After some thinking on the matter I decided to try an experiment. A few months before the summer I THOROUGHLY cleaned my filter and meticulously added the proper amount (ok maybe a little more than suggested) of DE to the filter. I left it alone for the entire summer. Now, we didn't have much rain here in DFW but I get a lot of wind and dust at my place. I watched the pressure gauge and to my amazement I made it about 4-5 months before the pressure got up to the point where something had to be done... Now, this is normally when I would backwash, then put in more DE... well, not this time.

I Did backwash but then immediately removed the filter and hosed it off... The first thing I noticed is that it came out much cleaner than when I pulled it after 3 or so backwash/recharges. The Next thing I noticed is that it was WAY easier to hose off this time around. The last thing I noticed is that there was not nearly as much gunk in the bottom of the empty filter housing as there was the last time.

So, I am done with the backwash/recharge. From now on, when the pressure hits the limit, its a full clean. 1 hr of my time, 12 bucks of DE and I am good to go for 4-5 more months (barring heavy rains).

I think that when you backwash, you knock off the DE layer from the filter mesh. The buildup goes to the bottom of the filter housing and sits there. Then the bit of DE you put back in end up unevenly distributed and also layers on top of the crud that didnt fall... this creates a really nasty layering of much and de that is hard to wash off and is frankly disgusting.

My Pool was super low maintenance this summer... literally all I did was put in my half gal a day in bleach and add MA as needed for PH and empty the baskets every few days.... no backwashing and my water got a lot of use... The water is too clear and I can see all the imperfections on my (in bad need of re plaster) quartz plaster.

 

[JoyfulNoise]

I find I only need to backwash once during the summer and once during the winter. I tear down and clean once per year (usually before the season starts). I use skimmer socks and a leaf canister on my suction cleaner, so I capture a lot of large and medium-sized debris before it gets to the filter.

What you're doing is certainly ok for you. For others who may have smaller DE filters where the pressure rises several times per season, doing a tear down and complete clean can get expensive.

What make, model and size DE filter do you have?


Sent from my iPhone using Tapatalk

 

[BuckeyeChris]

Man, I think I'm with the OP. I, uh, haven't been checking my psi as often as I should. But last year when I backwashed once, then full disassembled, the DE was in an uneven clumpy mess all over the grids.

Given that backwashing is like a 2 person job, with all that water just running down the driveway into the street...I think I'll just deep clean every nine months.

 

[pabeader]

I like this thread for one simple reason. It really points out what you can do when you have taken control of your pool. You learn what works for you. Clearly explain it so others can benefit from the experience. And feel confident in what you have done. Empowerment is awesome!

 

[bdavis466]

To add to this, the backwash valves are very restrictive (even the high-flow multiport valves) and add another gasket that needs frequent attention. Breaking the filter down is an easy job and not all that time consuming.

 

[JoyfulNoise]

To add to this, the backwash valves are very restrictive (even the high-flow multiport valves) and add another gasket that needs frequent attention. Breaking the filter down is an easy job and not all that time consuming.

Funny enough our QuadDE's come with an optional multi-port valve you can buy instead of the standard push/pull valves....assuming you like extra gasket maintenance I actually thought of getting one because I liked the idea of having recirculate mode but then decided it would be a waste of money as I would never use the "vacuum to waste" mode and it would require redo'ing the PVC lines going into the filter....just not worth it.

 

[Scoop]

Austintatious

I'm also located in the DFW area.

Here's my DE Backwash history and method since switching to the TFP pool methods in June 2014:

Backwash Date - PSI reading - Duration between Backwashes

May 15 2014 - 23 - 5 weeks

Nov 7 2014 - 23 - 6 Months

Feb 17 2015 - 23 - 3.5 Months

Jun 1 2015 - 26 - 3.5 Months

It's coming up on 6 months since my last Backwash was preformed.

Here's my Backwash method:

I backwash when my PSI rises to approx. 8 PSI above my "clean" PSI reading. I realize that's not generally recognized as the recommended procedure. It's been working ok for me so I'm staying with it after years of previously backwashing using a "pool store" rule of thumb frequency of once a month.

I purchased and installed the TFP site PSI Gauge about 6 months ago to get a better PSI reading with the 0-30 gauge vs the standard 0-60 gauges.

I'm not sure, but I think I can go longer lengths between Backwashes due to the # of Backwash/Rinse cycles that I perform with my Multiport Valve.

I run 10 Backwash/Rinse cycles. Here's what I do for 10 cycles:

- Multiport Valve to "Backwash" position. Turn on Pump, run for ~30 seconds or until the Sight Glass indicates a mostly clear flow.
- Multiport Valve to "Rinse" position. Turn on Pump, observe a momentary DE flow from Sight Glass. Turn off Pump after ~10 seconds.

After observing the Multiport Valve Sight Glass, I can get a consistently clear flow in the "Backwash" position (minimum to no DE observed in the Sight Glass) after 10 cycles.

After running the 10 cycles, I charge the filter with DE using the "80%" rule, reducing the DE charge amount by 20% from a new (new or completely cleaned grids) charge.

My DE filter uses about 3.5 Lbs DE, equal to 7 scoops using the blue Leslie's DE measuring cup. After the initial charge (after a complete removal and Grid/Filter cleaning), I'll charge with 6 scoops of DE going forward after each Backwash.

My best-case PSI reading (with a completely new or externally cleaned Grid set) is 12-13 PSI. The last time I replaced the Grids with my spare Grid Assembly was Sept 4 2013 .

Since then my PSI readings after a Backwash and before charging with DE has been the same as with a new Grid set and the PSI right after a DE charge has been 13-14 .

The PSI reading usually stays around 14-16 until it begins to rise in the days preceding the next backwash.

Based on my results, I don't pull the DE Filter on a scheduled basis. I'll pull it for a compete cleanup when I see my pre-charge PSI (after backwashing and before charging) increase by a few PSI .

 

[bdavis466]

Funny enough our QuadDE's come with an optional multi-port valve you can buy instead of the standard push/pull valves....assuming you like extra gasket maintenance I actually thought of getting one because I liked the idea of having recirculate mode but then decided it would be a waste of money as I would never use the "vacuum to waste" mode and it would require redo'ing the PVC lines going into the filter....just not worth it.

Even funnier (or sad), I have both the high flow multiport and the full-flo XF back wash valves sitting in my garage new and unused!

I plumbed a three-port valve to my waste line before my filter for the sole purpose of dumping calcium rich water as the need arises. Much less money than a multiport (either one or both) and far more efficient.

 

[Scoop]

Regarding Multiport Valves, I installed mine in Aug 2012. After 26 Backwashes, I haven't had to service the valve yet but perhaps I'm overdue for a gasket issue arising.

After having various issues over the years with the old Push/Pull Valve, the Multiport Valve has been a good addition to my pool equipment.

 

[Austintatious]

Nice post scoop.... From the looks of it my filter is about twice the size of yours... a 25lb bag of DE is good for 2 charges for my large DE filter ( ~70 sq feet I believe, its the biggest pentair makes )

I just got really mad the last time I cleaned the filter, the gunk was STUCK to it badly and it took forever to hose down. THe backwash process you described would take just as long as pulling and cleaning instead with IMHO much cleaner results.

 

[Manlymaid]

An acquiantance of mine likes the quad d.e. filter without a backwash valve. Clean it 4 times a year and is very owner friendly, ive taken to these filters as well for thier durability, theu can take a walloping and clean up fast, so if your intent is to never backwash, keep it in mind for your next filter.

 

[BuckeyeChris]

It was tricky to get the overlapping grids all back into place. I tried both having the cap upside down on the ground, or setting it down on top of the grids.
Also, had to find a harbor freight to get a torq wrench that measured in pounds per sq ft (for the outer sealing ring).

 

[Austintatious]

BuckeyeChris,

To clean mine, I don't take the filter grids apart... just hose them off from the ends looking as deep into it as I can.

 

[BuckeyeChris]

BuckeyeChris,

To clean mine, I don't take the filter grids apart... just hose them off from the ends looking as deep into it as I can.

Unfortunately (chalk this up to "next time I build a pool...."), my filter drain plug is 3 inches from the house's foundation, pointing right at it. Then we built a wood frame shed around it.

I tried to put in a right-angle PVC extension with a valve I could turn, but it didn't work out. I might need to take the Bissel out there with the attachment to just suck up the water from the lower half..

but, I will say, when I did take the grids out, there was some stubborn stuff at the bottom, under the grid frame.

 

[pabeader]

I was thinking of doing the PVC 90 on mine. Why didn't it work out for you?

 

[BuckeyeChris]

IIRC....The issue was in trying engineer it so I could unscrew it from the filter if needed. Which, because it has a 90 degree turn and then an extension, meant I couldn't just hard cement all the joints. I needed a disconnect somewhere right at the 90 degree bend. And if I didn't tighten the threaded pipe into the filter just right, it would leak, or if I needed to tighten it, the whole extension would not be level, as it's all attached.

Anyway, I'm sure some better engineering with some more appropriate floating/collared or non-permanent joints, and someone better and PVC cement than I, could probably make it work.

 

[Jaimslaw]

I've always wondered how you come to determine how much to recharge with DE after the backwash. I mean, how do you know what amount of DE is leaving the filter? Backwahsing would appear to increase the odds of the DE bridging (clumping between the grids) or having insufficient DE to get back onto the grids. Not saying that one could, with experience, come to know how much DE to put back after a back flush ... just that there would be increased odds for most ppl of under or over charging following the backwash.

 

[JoyfulNoise]

I've always wondered how you come to determine how much to recharge with DE after the backwash. I mean, how do you know what amount of DE is leaving the filter? Backwahsing would appear to increase the odds of the DE bridging (clumping between the grids) or having insufficient DE to get back onto the grids. Not saying that one could, with experience, come to know how much DE to put back after a back flush ... just that there would be increased odds for most ppl of under or over charging following the backwash.

It's pretty much experience as to the amount of DE discharged in backwash but it really depends on a lot of factors that are outside the users control. 50% is probably a "close enough" figure. What you have stated is exactly the reason why DE filters should be torn down and cleaned at least once per year - it ensures that you are not building up unnecessary amounts of DE in the filter and it allows you to inspect critical components for damage or replacement.

 

[Scoop]

Nice post scoop.... From the looks of it my filter is about twice the size of yours... a 25lb bag of DE is good for 2 charges for my large DE filter ( ~70 sq feet I believe, its the biggest pentair makes )

I just got really mad the last time I cleaned the filter, the gunk was STUCK to it badly and it took forever to hose down. The backwash process you described would take just as long as pulling and cleaning instead with IMHO much cleaner results.

I wish I could pull and clean the DE Filter Assy that fast . I have an old-style Nautilus SS tank with a couple of parts that I can't locate for replacements so that's one reason I don't pull my DE Filter Grids unless my PSI indicates the necessity to do a complete filter cleanup.

BuckeyeChris,

To clean mine, I don't take the filter grids apart... just hose them off from the ends looking as deep into it as I can.

That helps explain the speed of your filter cleaning. It's probably about the same time requirement, as you mentioned earlier, as my 10-cycle Backwash routine.

I've always wondered how you come to determine how much to recharge with DE after the backwash. I mean, how do you know what amount of DE is leaving the filter? Backwahsing would appear to increase the odds of the DE bridging (clumping between the grids) or having insufficient DE to get back onto the grids. Not saying that one could, with experience, come to know how much DE to put back after a back flush ... just that there would be increased odds for most ppl of under or over charging following the backwash.

This forum thread may help with your question. Several members reference the "80%" rule when determining the amount of DE to add after a Backwash.

I've used this method for a few years with good results. The last time I added a complete (100%) DE charge was in Sept 2013 which was the last time I replaced my DE Filter Grid Assembly.

What I've seen with my pool when Backwashing and observing the PSI readings prior and after Backwash cycles, is that with 10 cycles, I'm removing most of the DE in the filter as my post-Backwash PSI reading reads about the same as my "best-case" PSI reading with an externally-cleaned Grid Assembly.

I'm probably in the minority regarding the opinion of cleaning (removing and cleaning the Grids or replacing the complete Grid Assembly) on a timed basis.

I rely on my database compiled of PSI readings over time vs pulling the DE Grids at a predetermined elapsed time period.

I guess the main factor is the status of the pool water, PSI readings, etc. My pool has been running in cruise control since switching to this forum's TFP chemical maintenance methods in June 2014 .

 

[bdavis466]

I've always wondered how you come to determine how much to recharge with DE after the backwash. I mean, how do you know what amount of DE is leaving the filter? Backwahsing would appear to increase the odds of the DE bridging (clumping between the grids) or having insufficient DE to get back onto the grids. Not saying that one could, with experience, come to know how much DE to put back after a back flush ... just that there would be increased odds for most ppl of under or over charging following the backwash.

Exactly why I am against backwashing...You will never really know how much DE is in there