My experience with cleaning my DE filter grids

jtaves85mcss

0
LifeTime Supporter
May 12, 2012
190
Cincinnati, OH
Pool Size
22000
Surface
Vinyl
Chlorine
Liquid Chlorine
Thank you jblizzle very much for the time to write the sticky on cleaning a DE filter and for all the good pictures. http://www.troublefreepool.com/threads/72506-DE-Filter-Cleaning-Tutorial I would never have attempted to clean up my filter and give it a once over without the confidence and information provided there.

I would like to share my experience with cleaning my filter grids from a Hayward 3600DE Microclear. I am the second owner and the filter is 14 years old although the grids are likely replacements. This filter operated okay the first two of seasons I used it, with occasional back washing and recharging. Last season it needed a couple of additional back washes.

Getting ready for start of this season I thought I would give the grids a good cleaning and wash. Based on how long the grids were holding water after a good spraying and further reading here, I decided to do an acid wash. I proceeded to break the filter down to fit the individual grids into a large trashcan much easier than the whole assembly. I noted a few of the internal plastic frames were cracked and a few small holes in the fabric, but didn’t really closely inspect them at this point.

I followed the directions in this sticky and some of the forum posts like http://www.troublefreepool.com/threads/3853-Use-and-care-for-DE-filters to give them a TSP wash (5 cusp in 25 gallons) and soak for 4 hours. That went well and the TSP removed a bunch of gunk. I hosed them off thoroughly and decided to use a mixture of dry acid (sodium bisulfate) versus muriatic acid (its what I had on hand). I spent lots of time researching the quantity of dry acid to use and could not quite figure out the conversion, and decided to stay on the side of caution. I went with dissolving 6 pounds in three gallons of warm water then added to the can and filled to approximately 25 gallons. This seemed to go well as there was limited visible reaction upon inserting the grids. I soaked them for 4 hours in that mixture then rinsed them well. There was a noticeable difference in the time required for the grids to drain water so I considered this a success.

It took approximately 10 lbs. of baking soda to neutralize the 6 lbs. of acid in 25 gallons of water. I then soaked the grids in 2lbs of baking soda mixed with another 25 gallons of water to ensure they were acid free.

I let them air dry overnight and then inspected them. This inspection was easier after they were dry and revealed the bad news. Five of the grids suffered at least one or a combination of the following: notable series of holes along the vertical inner edge; significant cracks in the internal plastic frames near outer corners; holes that were beginning to form where either the top or bottom manifold alignment slots were wearing them; and pencil eraser size shredded areas where the fabric was separating at the bottom of the central tubes. Other than the cracked corners, none of this damage was readily apparent while the whole unit was assembled.

At this point I figured I was fighting a loosing battle if I attempted repairs and decided to get a replacement set of grids and purchased them locally for $175. About $25 more than some of the online retailers I found.

The last thing I wanted to do was limp to the middle of summer and find my filter blowing DE into the pool one warm Saturday afternoon and have to deal with it on short notice. Assembling the whole thing with new grids was pain free and my start up pressure was 5 pounds lower than last year.


Things I learned and take away notes for my future reference:
1. Older grids should be periodically and thoroughly inspected by removing them from the manifolds.
2. Use muriatic acid for the wash (if its necessary), a trip to the store to buy the right product would have saved my dry acid volume research time. (That research had a benefit though, as I learned a few things about the dry acid and plan to switch to muriatic to reduce PH in the future.)
3. Thoroughly rinse and let the disassembled grids dry prior to a first inspection - BEFORE beginning the soap and acid cleaning process. This would have saved me time and money trying to clean up grids that really needed to be replaced.
 
Re: DE Filter Cleaning Tutorial

Never use acid on the grids without first soaking overnight with detergent. Acid without detergent can harden oils onto the grids permanently. Acid washes are really only need when there has been calcium scaling on the grids.
 
Re: DE Filter Cleaning Tutorial

Jason, thanks for your input on this topic.

Can you elaborate or provide information on your experience or research with two items that I couldn't seem to find answers for in my research?

1. Reasons for an overnight detergent/TSP soak versus 4 or 5 hours (which is the general recommendation I found).

2. How to determine the need for an acid soak, i.e., calcium scaling. All I could find is general recommendation that if the grids held water more than 30 seconds to drain, then it was worthwhile to acid wash. Mine went from a 35 count to a 25 count after the acid wash. That was after spraying with a hose vigorously to the point of saturation then holding the grid up vertically with the bottom horizontal, hole at the top. What does calcium scaling present as a symptom, or what is the objective method for determining?
 
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Re: DE Filter Cleaning Tutorial

Overnight is simpler language that people are more likely to follow correctly. If you say 4 or 5 hours, an amazing percentage of people will soak for an hour and call it good.

Acid is only really useful when you have calcium scaling. Calcium deposits are normally fairly obvious, white gritty brittle deposits on the grids as opposed to fairly flexible/soft fabric. Marginal cases can be missed, but also won't cause much trouble.
 
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Sorry for the late reply Jason. Thanks for your input on the degrease timing and description of the calcium condition. I did think I had some slight buildup on my old grids after the TSP wash and rinse, you could see and feel it, but probably would not have been the end of the world to stop short of the acid wash and reuse them had they been in better overall condition. I should have slowed down and inspected, dried, and inspected them again each step of the way.

I will take this whole effort as a learning experience, with lots of knowledge gained thanks to the experts here at TFP.
 
its not that hard just take each grind out take a 50/50 muratis and water and slowly pour it over each part of each grid one​ gallon of 50/50 should do 8 large grids let it sit on each one for 10 seconds or so then rince really well with water , ( u had to rince them ahead of time of course) can get wiffy wear mask lol only takes an hour and ur done all back together and workn smile acid dangerous know ur stuff smile
 
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