Starting a Pool, Outflow from Filter reduces after 1 hour

[BartonSwimmer]

Hi all:
I am a pool newbie. Moved into a house over the winter and ignored the pool .. Now I am starting it back up. The pool was green.
Pool is in ground, large and with a DE filter.
Heres what I did:
1. Brough the TA and PH to range
2. Then I shocked the pool with calcium hypo shock. Once i got some clarity I was planning to use the methods listed on this forum.

The filter pressured doubled up and the outflow reduced dramatically within 30 mins. So I backwashed and tried again, even without adding any DE, the same situation repeated.
So then i decided to open up my DE filter (Pentair) and clean out the Grids. Removed them, washed them all out and started the filter again. Pressure was low and good.
Added DE powder. Within 30 minutes same issue repeated itself. I have done this multiple times over multiple days and seem to be stuck.

I have noticed that backwashing does not seem to help, if i open up the filter, and spray wash the grids, I can get 30 mins to a hour of run time before the pressure doubles and flow slows down to a trickle.

Questions:
1. Is this expected behavior and I should repeat until the pool is clear?
2. Or is this unexpected and there are other things i should be looking into?

I found some other threads that seemed similar but there did not seem to be resolutions to those issues. Backwashing is called for twice or thrice a day. My frequency seems to be very high.
I wanted to basiclally get told : Stay the course, this is the way or told that I am doing /or my system is doing something wrong.

 

[kimkats]

What is happening very normal with a DE filter is it doing it's job.....BUT you do need to step back from using the shock you have been adding as it is not the proper stuff to clean the algae.

How are you testing your water? The back bone of good pool care is a good test kit of your own. Test Kits Compared

Once you get the test kit you need to SLAM your pool as seen here: SLAM Process We even have a video of it:

Kim

 

[BartonSwimmer]

I came to this forum after running into the issue above so was not aware of the SLAM recommendations. I It was interesting to see the SLAM recommendation of using liquid chlorine/bleach since using shock over was chlorine was the recommendation of the chain pool store ...
have a taylor Tech. FAS_DPD kit, which has i believe the reagents needed.

The SLAM process explanation seems pretty straightforward. A couple of questions
1. During the SLAM process, am i still running the pool in filter mode? Or should i be in recirculate mode, bypassing the filter?
I ask because if I am in Filter mode, i will most probably have the low flow issue within an hour and hence need to clean it
2. from your response it looks like the frequent cleaning is expected from a DE filter. The high frequency of the pressure jump caught me by surprise. I am guessing that I must be having enough algae to block up the filters quickly
3. Why is Liquid chlorine preferred over Cal Hypo shock? It adds Calcium but isn't it more efficient in delivery because it is a dry system vs, getting liquid bleach?
4. From past experience, hHow much time will it take for me to see some positive results? And what should i be looking for quantitatively?

Thanks for the response

 

[kimkats]

was the recommendation of the chain pool store ...

And who sold you that shock? That is their bread and butter right there. Will cover the pool $tore a bit more later.

have a taylor Tech. FAS_DPD kit, which has i believe the reagents needed.

SWEET! That is just what you need. You also need the other tests as well but you can get them in the Taylor 2005 if you wallet is hurting. Now if your wallet is a little fatter then I would move up to the Taylor 2006C or the TF-100. Here is a link to show them all to you: Test Kits Compared

1. During the SLAM process, am i still running the pool in filter mode? Or should i be in recirculate mode, bypassing the filter?
I ask because if I am in Filter mode, i will most probably have the low flow issue within an hour and hence need to clean it

I really need to see a pic of what your pool looks like now so I can judge how far into the process you are before I answer this one. For right now just run it in recirc. when you cannot be there to babysit and clean as needed.

2. from your response it looks like the frequent cleaning is expected from a DE filter. The high frequency of the pressure jump caught me by surprise. I am guessing that I must be having enough algae to block up the filters quickly

You are correct. The DE filter is the best for keeping a pool clean but it is almost too good when battling algae as you are seeing.

3. Why is Liquid chlorine preferred over Cal Hypo shock? It adds Calcium but isn't it more efficient in delivery because it is a dry system vs, getting liquid bleach?

The only way to get rid of the Calcium from those tables or CYA from the other kind to tablets is to drain and refill some of the water as over time both of these build up until they get too high and start causing problems.

Liquid bleach/chlorine-see if your pool store sells liquid chlorine. If so that is your best bet price wise and for doing the job! It mixes better in the water and does a better job killing the algae. Another risk of the power is it sitting on the bottom of the pool and causing problems that way.

4. From past experience, hHow much time will it take for me to see some positive results? And what should i be looking for quantitatively?

Again this is where I need to see where you are now.

SO help me help you.............can you please fill in your signature? Go up to your name and click on it. Tell us what kind of pool (in or above ground, plaster or vinyl), kind of filter (I know DE from reading your posts but this will put it on each post and makes it easier to everyone down the line), what you are using to test.

We do need to know your full test results especially the pH and CYA. Please order a full test kit asap!

Kim

 

[JJ_Tex]

I also may be reading your initial post incorrectly, but a common misconception is that your filter gets rid of algae.

Your chlorine kills the algae, and your filter cleans out the dead algae. Chlorine is your most important step now. As Kim said, if you need to bypass your filter now and focus solely on the chlorine, that is fine.

You mentioned you had a test and added shock, but I never saw test results. What is your CYA level and FC level? Make sure you are at the SLAM level for your FC, based on your CYA. Chlorine / CYA Chart - Trouble Free Pool
Most people make the mistake and have their FC too low to kill the algae.

 

[Casey]

DE filters are the best filtering systems you can have but they need babysat during a full blown SLAM. I'll tell you this... depending on how big your pool is and how much debris is at the bottom...if you get everything in line with testing, keeping up the SLAM, brushing, vacuuming and cleaning the filter, you can clear the pool in record time verses someone using a sand filter. It's really up to you on following the SLAM to a T!

 

[BartonSwimmer]

Hi all:
Wanted to give an update.
Got myself some HDX 10% chlorinating liquid, and have been running the pump non-stop for 3 days. Added a gallon per night for two days straight. Then tested the water
FC was 0.6 in the morning.
Last evening added another gallon of liquid, today AM, the FC was 0.6, CC=0.8
My CYA levels are at 30 and the water is pretty hard at 600. Qualitatively my pool outflow seems to be low but not as low and color seems to be better. But this seems to be so sloooow..
My FC is not getting up to 2 (the minimum level) and the SLAM level of 12 is way off. Should i be uppping the amount of chlorine? The pool math calculator told me to expect +4 FC due to my addition, but i do not see it (note: after 8 hours)

Am i doing it correctly? I seem to be consuming chlorine so quickly, is this expected? Thanks for all the advice/help and keep it coming

 

[aeh0603]

Yes, at the beginning of a SLAM your FC can go down quite quickly as it gets consumed by algae. If you are only adding 4 FC once a day, then you are not adding anywhere close to as much FC as you need.

At this point you should be testing FC as much as possible (no more than once an hour and no less than 3-4 times a day). Each time you test you should add enough FC to get back to your SLAM level. Since you said your CYA is 30, you need to be dosing FC to 12 each time you test.

You should also be keeping an eye on your filter pressure and clean your filter whenever the pressure rises by 25% over clean pressure.

You should also be brushing your entire pool at least once a day.

 

[kimkats]

You HAVE to add FC at LEAST 3 times a day. Otherwise you are just irritating it instead of killing it.

Now saying "at least 3 times a day"...............that is bare minimum...........it will take a while to clear so the more you can test and add FC to get and KEEP it at SLAM level for your CYA the faster it will go.

 

[wireform]

It hasn't been mentioned yet but if there are any solid organics in the water such as leaves and such, you'll need to get that out asap as that will consume the chlorine fast too. There should be absolutely nothing but green water for the chlorine to treat.

 

[BartonSwimmer]

Wanted to post an update.
So I think I am following the correct procedure since the weekend. Last two days, I typically end up pouring a gallon of 10% chlorine, once first thing in the morning, once around 3 pm and once at 7 pm. The FC level typically comes down from 11/12 to 5 or 6 over the night.
The pool is now a whitish green color, seems better than last week.
So i have gone through 15 gallons of 10% chlorine. I feel a bit weird, going to curbside and loading up jugs on a daily basis
I am measuring only FC and ignoring testing everything else till the pool is clear. (Brushing the pool two times a day )
Am i on the right track in terms of what I am doing? any steps I am missing?

 

[kimkats]

MUCH better!!! Good job upping the addition of chlorine.............can you do one more step further?? Test and add right before you go to bed to make it 4 times a day?

If anyone asks what you are doing when you buy or they see the used jugs...............just look at them and start crying........"one day it will come out" and walk away LOL

 

[BartonSwimmer]

So things are looking better. the pool is still cloudy but I can see the first step. This is approx Day 10 of the SLAM. And i ran out of FAS-DPB agent over the weekend i should be getting more today.
A couple of questions:
1. I think some of the cloudiness/sediment in the pool is from DE powder. How can i make out the difference between it and oxidized algae? By touch? what should i do to clear it out?
2. How long does it take for a well functioning DE filter to clear a 25K pool?

 

[wireform]

So things are looking better. the pool is still cloudy but I can see the first step. This is approx Day 10 of the SLAM. And i ran out of FAS-DPB agent over the weekend i should be getting more today.
A couple of questions:
1. I think some of the cloudiness/sediment in the pool is from DE powder. How can i make out the difference between it and oxidized algae? By touch? what should i do to clear it out?
2. How long does it take for a well functioning DE filter to clear a 25K pool?

The DE will settle to the bottom and won't cloud the pool for too long once it exited the pool returns. Algae is usually brownish and will become suspended the moment it's disturbed almost like dust flying.

 

[BartonSwimmer]

Its been 14 days since i started the SLAM. I need to figure out the exit from SLAM. I have overnight loss of around 1 ppm and my CC is 0.5. However my pool is is not clear. There is cloudiness that has been reducing every day. For example, i still cannot see the bottom but can see the sides and my steps.
Should i exit from SLAM chlorine levels to normal level? Or wait till pool is clear
Should i apply a defloc agent to the pool to collect the material on the bottom?
Advice is appreciated.

 

[JJ_Tex]

No defloc, just continue the SLAM. How is your filter pressure doing, do you need to backwash?

 

[mknauss]

It is quite odd for a DE filter to take this long to clear the pool.

We believe it best to stay at SLAM levels until clear. But it is your pool, if you wish to let the FC come down to the target range for your CYA, it is up to you.

Take care.

 

[IceShadow]

Be sure you’ve checked behind removable lights, inside the skimmer throats, ladders, steps, etc. to see if any algae is hiding somewhere.

 

[BartonSwimmer]

It's very helpful to hear from experienced folks who can sense if something is not right. I took the oddness of the DE filter/backwash comment and acted on it. I had backwashed before but was not sure if it had worked. I now opened up the filter, cleaned out the grids and ran the filter overnight and now the pool is almost clear !! Thanks a lot guys, it has been very very helpful !!
May need to debug why the backwash was not effective.. maybe too much dead algae??

 

[mknauss]

May need to debug why the backwash was not effective.. maybe too much dead algae??

At times, you just need to clean the grids completely. Backwash only sort of disturbs things.