My pool store told me they don't recommend backwashing! Huh? Empowered Owner!

devon

0
LifeTime Supporter
Jun 12, 2015
20
Thousand Oaks, CA
Thanks to this site, I feel so much more empowered now when I got into my pool store.
So before my remodel, I never understood what backwashing was / did.
I would always just take apart my filter and hose down the grids every time the pressure rose. It was a real PIA.
So now I have read here what back washing is and why you do it.
I ordered a 2" backwash hose and go to attach to bottom of the push/pull slide valve. Huh? nothing to attach it to.
After much research I realize I need to get a union with a slip fitting into the bottom of the slide valve with a threaded fitting on the other side to screw in the reducer so the hose fits over and can be then clamped with the hose clamp which came with it.
(Providing extra detail in case someone else is confused like I was)
backwash.jpg
Anyway, I go to the pool store to get the union and they tell me they don't recommend backwashing the filter.
I ask why, and the guy says first of all you lose DE when you backwash and you don't know how much more to add, secondly you may blow out the grids with the reverse pressure.
I tell him that means I have to clean the filter at least once a month when my pressure rises 10%.
He said I should only need to clean the filter ever 2-3 months.
So I said but what if the pressure rises before then - he said well then you need to clean it sooner.:confused:
He also suggested I get some grid cleaner. I told him I can just clean with muritic acid - what does your stuff have in it - he says, well it contains muritic acid - but heavily diluted. You have to be careful using muritic acid. I said I just would dilute it like 10-1 and soak the grids. He said that this product makes it much easier.
Anyway, I thanked him and was about to pay for my part - and then he ask's
You're using 2 forms of chlorine in your pool right?
I said no, just liquid chlorine.
He said you should really be using 2 forms of chlorine so the sun doesn't burn it off (So. Cal - High 80's already all week)
I told him I have enough conditioner in the water already to help prevent that and that I don't want to use tablets anymore to keep my CYA levels down. He just kinda stared at me and said, well you need two forms of chlorine to prevent against loss - just repeating the same thing again.
I told him I add adequate liquid each day to ensure the proper level.
He just said - well you wouldn't have to add every day and you have extra insurance in case the level gets to low (now more half-heatedly because I stood the confidently answering his question with what I now know are perfectly educated responses)
Just paid for my parts and left with a smile.
Anyway - just had to share.
Devon
 
Just a thought. I average less than 1 backwash a season and have never needed to acid-treat my DE filter after 4 years. I believe that is a "when needed" situation. When my pressure rises above recommendations, I then use the "bump" handle and everything is fine. I probably "bump" 6 - 8 times a season.
 
Need to acid wash your DE grids is going to greatly depend on your calcium levels, people in the Southwest and California tend to have much higher calcium levels than people on the east coast.
 
I really don't backwash my DE filter. I don't have a bump option. Pentair recommends 100% replacement of DE after backwashing, not 80%. So after backwashing, you will not end up with the correct amount of DE in your filter. I tend to just tear it down and give it a thorough cleaning. Do an inspection. Then re-add DE. Takes a half hour. Then I know it's running at the correct DE level. I took mine apart after backwashing for a couple minutes and the mess in there was ridiculous (after an algae bloom). Decided then and there that there was no advantage to just backwashing and adding more DE to a very dirty filter system. But I enjoy the mechanical aspect to things like this, and don't see tearing it down and cleaning it as work.

So, mechanically speaking, I don't think the guy gave you bad advice. What he told you will certainly ensure proper DE level and not expose your grids to backwards flow. It's just a little more work, but certainly does no harm.
 
Thanks inflatable. Your method WAS my method for about 15 years. Yes I know about a mess during/after fighting algae. There were times I had to take it apart 2X in a day because the pressure would rise so much when I was brushing down the pool coated with algae. Too much CYA from tablets for 15 years, without a water drain ever, is what I now suspect. With the new pool, liquid chlorine only and I was trying to save myself even more time cleaning using the backwash method.
The manual also says to replace 100% of DE after backwash. So what is the problem with too much DE? Just potentially higher PSI?
Devon
 
Thanks inflatable. Your method WAS my method for about 15 years. Yes I know about a mess during/after fighting algae. There were times I had to take it apart 2X in a day because the pressure would rise so much when I was brushing down the pool coated with algae. Too much CYA from tablets for 15 years, without a water drain ever, is what I now suspect. With the new pool, liquid chlorine only and I was trying to save myself even more time cleaning using the backwash method.
The manual also says to replace 100% of DE after backwash. So what is the problem with too much DE? Just potentially higher PSI?
Devon
Too much DE when recoating will make pressure rise and flow slow down. No different than being clogged with plain earth.

Incomplete backwashing - and you know you never get all of it - could, over time, lead to this
P01_zpsa1b7b98e.jpg


THAT is a clogged filter.
 
There were times I had to take it apart 2X in a day because the pressure would rise so much when I was brushing down the pool coated with algae.

I think if I was in the middle of something like a dirty/messy cleanup/SLAM, i'd probably do some backwashing. Hate to break something on disassembly in the middle of a SLAM. Would have to think on that.

On the too much DE thing; it's like trying to clean your pool with a dirty filter. And you think you are starting fresh. Like Richard said, less flow and more pressure. Typically that's when TFP tells you to backwash, but you just did. So you didn't really gain anything.

I should say that when I saw how much dirt was in my filter after a couple minutes of backwashing, the fluid was running clear. So a person would think they were starting with a clean canister, and it wasn't even close.

So I weigh my DE, get rid of any accuracy concerns. There is a well liked youtube video of a guy giving instructions on how to clean the Pentair 4000 series and he tells them to put ten pounds in a 4048. It only requires 4.8 lbs. Keep that up, and you quickly have the filter in Richard's picture.

Ryan
 

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thanks guys. Not opposed at all to the full clean. It was just that my OLD metal filter had nice easy holes in the bottom. You just slide the grids in and out. When that got replaced with the Jandy - the grids are all connected and you take them all out together - sounds good except I could never really get ALL of the DE out between the bottom unless I took them all apart - putting those back together was a PIA. That is why I was looking forward to a backwash to help avoid as much of that. I will experiment with backwash and see. Otherwise, back to full cleaning.
 
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