time for new filter

[optimator]

I've had the perflex EC75 DE filter for about 12 years (pool details below). I just re-did the plumbing to fix some issues. At restart the filter body split. One option for me is to just buy another so I don't need to worry about plumbing again. The DE system works well when I get algae blooms, which I get every summer when the water hits 90+ and I neglect the pool for a week. My past issues have been:
-the "bump" is pretty worthless. If I don't change the DE it clogs right away.
-opening to really clean the "fingers" is a pain
-the filter is probably undersized for my pool

I am also considering the FNSP 60 and would like to hear opinions on this. It seems more difficult to clean than the routine EC75 cleaning. I used a 300# sand filter for 2 years (still have it), but it didn't work well for my pool (too small; pump too strong; poor water clarity). Cartridge filters seem too expensive.

Pool (40 yrs old):
33000 gal plaster with long 1.5" pipe runs from skimmer and drain, 2" returns
motors: Whisperflo 1 HP #WFDS-4 2 speed 1.65 sf, AO Smith 1.5HP

Thanks for your advice,
-Glenn

 

[PSW]

Hey Glenn, you've certainly got a handful of options!

Sounds to me like you have pretty much ruled out a sand filter, because it won't do the job you are looking for.

As far as DE vs Cartridge, it is really up to your preference. DE will filter better than a cartridge, but they are a pain to clean. Also, the FNSP60 is pretty much as expensive as a cartridge filter.

About the annual algae bloom...
I realize that it takes frequent attention to keep your water balanced and algae-free, but if you can do that, you will avoid running that algae through your filter (thus reducing cleaning and wear/tear). And even when you filter out the particles, you will need to SLAM your pool to prevent another outbreak.

 

[pwrstrk]

Welcome to TFP !!

Maintaining the proper chlorine levels for your CYA level will go along way in keeping you pool algae free. With the higher water temps your chlorine demand will also increase.

Spend sometime reading in pool school. Here's a good place to start. pool-school/pool_water_chemistry.

pool-school/chlorine_cya_chart_shock

How are you testing your levels ? I would suggest you look into one of our recommended test kits. It's a small investment for the most accurate way to test your levels. I use the TF-100. pool-school/pool_test_kit_comparison

 

[optimator]

Thanks for the tips. I'm pretty familiar with the chemistry, having dealt with it for 15 years. My problem is that sometimes I travel or am too busy/forget for a week or 2, then the trouble starts. I suppose I should automate the chlorination, but haven't done it.

I guess my question is mostly: should I opt for the bigger DE filter with my crappy flow? I imagine that will help with longer filter clean intervals and keep flow better. Was my EC75a (40 ft^2) undersized? I'm leaning toward that since it is only $430 and would be trivial to install. The FNSP-60 (60 ft^2) is $700 + a valve and replumbing. The cartridge CCP-520 is ~ $850 + valve, replumbing, and big replacement costs.

New question: When I ran the motor on low speed with either the DE or sand system, I got so little flow it was no good, even 24 hrs/day. Ideas on the cause?

 

[duraleigh]

Hey, optimator, Welcome to the forum.

I know you are asking about filters for now but you are asking for the wrong reason. Filters have VERY little affect on controlling algae in your pool and, regardless of size, there is no filter that will save your pool when your chlorine is allowed to drop as low for as long as yours apparently has.

Whatever filter you get, read the "ABC's of Pool Water Chemistry" in Pool School. You will find that no amount of filtering will get live algae from a pool......That's the job of adequate chlorine and you cannot manage a successful pool without it.

 

[optimator]

True, but after shocking the DE filter does a far better job of filtering than the sand did. I avoid vacuuming to waste to do my part for the Cal drought (and really high water prices).

 

[optimator]

After lots more research I am now leaning toward the Sta-Rite S7M400 cartridge filter (400 ft^2) @ $700 (I see now no valve is needed). My pool gets lots of dust & hair, so I need to disassemble either a cart. or DE fairly often anyway; they seem similar in effort. With the cart. filter life, that will be more $ though. For me, however, big problems with the DE are the water loss and the DE washing down into my neighbor's yard. I get about 80% of the DE into a bucket, but the rest is a mess. Also, the head loss from a valve is an issue due to my big loss from the 1 drain & 1 skimmer lines. My old DE was probably 1/2 the size it should have been. For me sand is a definite no because of the water cost, even if I could get a system working properly.

I am thinking of converting my second pump to a vac-to-waste tool for times like algae bloom or the time mud washed into the pool.

Are these reasonable ideas?

 

[duraleigh]

For me sand is a definite no because of the water cost, even if I could get a system working properly.

You may want to review that. Typically in the US, water seems to cost $5-10/1000 gallons so a 200 gallon backwash would cost you about $2.00. I do not understand what you mean by "system working properly". Sand is generally the most forgiving of the 3 types of filters.