SLAM going on FOREVER

matt.burba

Active member
Aug 14, 2015
40
Okemos, MI
Hello all -- I've been a member for several years, and had good success, but I'm really struggling to get my pool open this year. I have been in SLAM mode for two weeks as of today, and while I'm seeing progress, my rate of improvement is so slow that I'm afraid it's going to be time to close before the kids can swim in it!

Here are my numbers:
FC - 26
CC - 0
CYA - 55
TA - 135
CH - 220
Salt - 3500


The Chlorine levels are not falling much overnight, so the pool is staying well over 20 ppm FC. I've been pouring in a gallon of sanitizer every third or fourth day.

Any thoughts? How can I speed this up?
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
20,152
Laughlin, NV
Your FC levels are staying there and you are only adding a gallon of liquid chlorine every 3 or 4 days?? A gallon of 10% is 5 ppm FC in your pool.

How are you testing your water chemistry?

What filter type do you have? Please add that to your signature.
 

matt.burba

Active member
Aug 14, 2015
40
Okemos, MI
20K gal, IG fiberglass, 175 sq ft cartridge, Hayward Tristar two speed pump, installed fall 2012, Taylor test kit, spa with overflow option, Hayward "Sense & Dispense" with pH & ORP continuous testing and muriatic acid refill tank and SWG connected.

This used to be my signature, not sure why it didn't print.

I'm using a Taylor K-2006
 

matt.burba

Active member
Aug 14, 2015
40
Okemos, MI
Yes I'm adding about a gallon of 12.5%, adds about 6ppm. I did spike it at the beginning of the process (two weeks ago). My point is that it is not rapidly losing FC like I would expect if there was algae still alive and well. It's almost like there is a lot of dead algae that is not getting cleaned out?
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
20,152
Laughlin, NV
It is there, I did not catch the cartridge as it does not say filter.

Most cartridge filters work reasonably well in clearing a pool. That one is quite small -- are you cleaning it when the pressure rises by 25% over clean pressure?
 

matt.burba

Active member
Aug 14, 2015
40
Okemos, MI
I'm testing my water chemistry with a Taylor K-2006 kit. I've turned off everything and am adding chlorine manually. I've been cleaning the filter every day or two -- sometimes longer when I've been gone on business trips. The pump has now been on 24/7for 14 days.
 

aeh0603

Well-known member
Apr 6, 2016
196
San Diego, CA
How often are you brushing? Do you have any light niches or ladders that might be hiding algae? What about the skimmer or weir door? If you have other features like a fountain, auto fill, waterfall, etc. are you running the SLAM level chlorine through them regularly?

Also, what does you water look like now and what has the progression looked like over the last two weeks?
 

duraleigh

Admin
Mod Squad
TFP Expert
Platinum Supporter
LifeTime Supporter
In The Industry
Apr 1, 2007
32,127
Sebring, Florida
A properly conducted SLAM will usually show SOME improvement daily. It sounds like you are being a little cavalier about your chlorine dosing and testing but I can't tell that for sure.

Your filter's capacity is quite influential on completing the SLAM. An undersized filter can slow things interminably but you should be able to witness that by observing the psi rise and cleaning as necessary. I assume the filter is not damaged in any way. A torn cartridge will never allow the pool water to be crystal clear.
 

matt.burba

Active member
Aug 14, 2015
40
Okemos, MI
I did an OCLT last night -- it fell from 27 to 23. I have been brushing, every couple days. Perhaps I could be more consistent?

The filter seems to have very good flow -- I'm surprised to hear that the system might be undersized. I feel like I have checked the sizing before (a few years ago I had some flow problems), and I thought I had the right size. I'm going to check again.

I haven't taken pictures of the progress but I can say that it has improved, albeit very slowly.
 

matt.burba

Active member
Aug 14, 2015
40
Okemos, MI
When cleaning my filter this morning, I just happened to check out the top of the filter and found a bunch of algae growing. Just cleaned that out, hopefully that will help. Brushed the entire pool/hot tub again.

How often should I be cleaning out my filter during a SLAM?
 

matt.burba

Active member
Aug 14, 2015
40
Okemos, MI
I’m cleaning my filter even though there hasn’t been much of a pressure change at all. Is that a problem that I’m cleaning it too much?
 

matt.burba

Active member
Aug 14, 2015
40
Okemos, MI
Also I’m running my robot pretty much non stop. I’m finding these things in my robot when I clean it out. Probably have cleaned about twenty out so far. They’re living deep enough that I can’t see them below the haze to scoop them out with my net.

107922
 

duraleigh

Admin
Mod Squad
TFP Expert
Platinum Supporter
LifeTime Supporter
In The Industry
Apr 1, 2007
32,127
Sebring, Florida
I'm no biologist, either but I have been to a "boil" more than once and they all look just like that! :oops:

How did they get there? I'm guessing but you either have had almost non-existent chlorine in your pool for a long time or you have some birds who are using your pool as a dining room and they are not doing a good job of cleaning up behind themselves..