Does anyone run two filters?

[ksguy]

We have a 16x32 AGP sanitized with bleach. We currently run a Pentair 342001 1.5HP VS pump and a Hayward EC50AC DE filter. I went to DE years ago after we just could not get the crystal clear water I wanted using sand. Based on everything I'd read, the DE should be able to last several years. This has not been my experience. Typically shortly after spring opening I wind up replacing the DE due to garbage that gets in and the inevitable algae that shows up late spring before I open.

Last year I put an old sand filter alongside the DE and set up my plumbing so I could route water through sand during opening so I could easily backwash and keep going without ruining my DE. Only after water was clean would I switch back over to DE. However, we've got dogs that love to play in the pool, and with those tracking grass and dirt in, and heavy usage from my kid and dust from the nearby pasture in the summer, the DE seems to just barely make it through a year anyway. Ultimately a regen only gets me a few days before pressure rises.

Well this past winter, I forgot to pull the plug on my sand filter and of course it exploded when it froze.

I'm going to get another sand filter but this time I'm considering just putting it permanently in series before the DE so I can catch the big junk and backwash it out, then let the DE do the easy job with the small stuff. Does anyone have experience with this? Will I be overworking my pump?

 

[reggiehammond]

Don't recall ever hearing anyone doing what you're doing...

Algae is not related to filtering, it's lack of sanitation (Free Chlorine.) Algae and DE Filters lead to lots of problems because the filtering is so effective.

I typically break down and clean my DE filter 2-3 times per year. I would not expect it to ever go a full year, however I do not backwash mine. I find it easier to just break it down and clean it, and know how much DE is inside (about a 20 min process.)

How do you test water chemistry today? You might consider a salt water chlorine generator, which makes keeping the pool algae-free quite a bit easier. I bet if you can maintain FC to never fall below minimum, you will find your DE filter performance greatly improved.

The Free Chlorine and Cyanuric Acid Relationship

Managing your cyanuric acid and Free Chlorine levels is key to stabilizing your pool. Learn how these two items affect each other.

www.troublefreepool.com

 

[ksguy]

The algae issue is typically only at pool opening. The rest of the year is it just garbage and sediment from wind and general pool activity. Skimmer basket socks don't seem to help too much other than cotton from cottonwood trees which was wreaking havoc on me for awhile.

I test chlorine levels at least twice a week with the TFP chem set, and test pH more often than that with a digital meter. I keep stabilizer level around 55-60, free chlorine around 5ppm, and alkalinity around 100ppm. pH tends to drift upward and I keep it under control with muriatic acid as necessary. Occasionally I'll do a CC test to make sure I'm in good shape, and sometimes shock it in the evening and do an overnight test to be sure I'm good. Under "normal" maintenance conditions 12.5% bleach dose is around 55oz per day. I'll do a bit more if the dogs had a particularly crazy day or if I mowed and stirred up a bunch of grass and dirt that blow in. I have it figured out by weight and pre-measure a bunch of jugs so they're just ready to go and my wife doesn't have to measure anything if I'm not around - just dump in a jug near the return. We use a floater with tabs if we're gone. I don't really worry about stabilizer increases from tabs for a few days, considering that we top off with fresh water to make up for splash losses, etc.

I've considered a saltwater generator for a long time but our steel walled pool is already 23 years old and showing quite a bit of rust around the base. This is even after disassembling a few years ago and wire wheeling down to bare metal, spraying galvanizing paint, then two nice coats of SW exterior oil paint. I think saltwater would just hasten the pool's demise and I'm not in a position to drop $10K+ on another pool just now.

 

[MITBeta]

Based on everything I'd read, the DE should be able to last several years.

Where have you read that? Like Reggie, I have to backwash and/or break down my DE filter 2-3 times per season.

I wind up replacing the DE due to garbage that gets in and the inevitable algae that shows up late spring before I open.

I see the problem: you're opening the pool too late. Much easier to open early and maintain it than open late and fight a mess.

 

[ksguy]

Where have you read that? Like Reggie, I have to backwash and/or break down my DE filter 2-3 times per season.

I don't remember, it was years ago. I decided it was a load of garbage within a year, but that's no longer the point. I'm doing maintenance on it each year like you two.

I see the problem: you're opening the pool too late. Much easier to open early and maintain it than open late and fight a mess.

Again, not the point of the post. This is great advice for some people, but we show signs of algae by mid-April, and we still have freezing weather then. Even with the solar heater, the water is not consistently warm enough for our comfort before mid to late May. I'm not opening my pool 6 weeks before we can use it just to avoid some algae.

 

[PoolStored]

Sorry you haven't gotten an answer to your question. I get it. You don't believe you have an algae problem, you want the benefit of the DE filter for clarity, but don't want to clean it often. You think having a sand filter first, followed by a DE filter would allow you to filter most stuff and backwash, while the DE filter would "polish" the water.

One option:

Add DE to a Sand Filter

A clean pool filter will increase the efficiency of your pool! ... your filter are to backwash it, clean the manifolds and grids, and add new DE.

www.troublefreepool.com

Not sure if it is advisable to put two filters in series, may be a bit of pressure...let's ask the experts...

@ajw22 @JamesW @mas985 @1poolman1

 

[Flying Tivo]

I asked the same question when i joined a few years back. You can get yourself a robot and that will act as a second filter and scrubs your pool too.

 

[JamesW]

Maybe get a TR-140 sand filter and then a CCP520 cartridge filter and then a FNS Plus DE 60 filter.

This way, you filter successively finer dirt.