My SLAM Story

[smoliakj]

Hi folks,

So… I’ve had issues since the start of the season (my first full season as a pool owner) which led me to TFP and the purchase of a TF-100 kit. I had significant CYA issues and basically drained 3/4 of my pool to sit at my current 100 CYA level. (Pool store recommendations which I’ll never trust again). My pool has been clear the entire season however I have been unable to keep free chlorine at all. My SWCG has not been able to keep up. I have noticed the “brown dust” in the crevasses of my liner or the seams that continues to collect which has been suggested to be dead algae. So I decided to start SLAMing at the higher and not recommended 100 CYA for a FC of 39. I started my SLAM three days ago. I have literally dumped pail after pail into the pool of liquid chlorine and don’t see to be getting anywhere. Today I tested this morning at 31 and had to dump in 4.5 pails to get to 40. (APP said only two pails but I tested after 30 min and it needed more). Once I get it to 40 about two hours later it was back down to 38 in full Sun. I added two more jugs. I just checked after a few more hours and it’s back down to 31. So I added another 2.5 jugs. This is day three and by far the worst day. My pool is starting to smell like bleach it seems. I am Canada so the bleach is Clorox Performance (7.55% Sodium Hypo) per 3.57 L jug.

I have literally no idea why my chlorine demand is so significant. I have been brushing and had my robot cleaning steady and my water is crystal clear. I also don’t have any real “voids” I can check to find hidden algae. I will add pics. Please help!!

I know the forums say “stay the course” but I’ve literally dumped 80$ in today with little headway and this is day 3!

My numbers: TA 200, PH 7.5, CYA 100, CH 175, CC’s 0.5

 

[smoliakj]

First pic of a small spot of the “dust” I’m seeing

 

[Mdragger88]

I guess you’re now seeing the reason behind the “not recommended” cya of 100.
It gets expensive fast. Also the ph test is invalid at fc levels above 10ppm- so don’t adjust that until slam is over & fc has fallen.
The SLAM Process is not generally a one/two day event. Often a week or more depending upon the severity at the start.
Your pool looks quite clear - I imagine u are nearing the end. The reoccurrence of the dead algae u are seeing should become less & less. Have u done an Overnight Chlorine Loss Test?

If u can exchange more water to lower your cya it would help use less bleach & testing reagents. During the day u can use a 5ml sample & every drop counts as 1ppm to conserve reagent. But for the Overnight Chlorine Loss Test be sure to use the 10ml sample - each drop = 0.5 ppm.

I see lots of algae hiding spots- skimmer, weir doors/foam, light niche (the hole the light sits in) , drain covers (there’s usually a bowl type situation under that cover that traps untold nasties) , step trim, return jets - they all need to be checked & brushed.

For a successful SLAM Process you need to continue to MAINTAIN Slam level fc for your cya until you meet ALL 3 end of slam criteria-

You are done when:

CC is 0.5 or lower;
You pass an Overnight Chlorine Loss Test
AND
the water is clear.
(Crystal Clear w/no algae dead or alive)

*Check & scrub every nook & cranny where it may hide (light niches, drain covers, ladder handrails, skimmer throats/weirs, etc.)
*Run slam level water through all water features & lines for at least a couple hours a day during the SLAM Process.
*Brush & or vac daily (this breaks up biofilms that algae uses to protect itself from chlorine)
*Backwash/clean filter when pressure rises 25%over clean pressure.

 

[smoliakj]

I guess you’re now seeing the reason behind the “not recommended” cya of 100.
It gets expensive fast. Also the ph test is invalid at fc levels above 10ppm- so don’t adjust that until slam is over & fc has fallen.
The SLAM Process is not generally a one/two day event. Often a week or more depending upon the severity at the start.
Your pool looks quite clear - I imagine u are nearing the end. The reoccurrence of the dead algae u are seeing should become less & less. Have u done an Overnight Chlorine Loss Test?

If u can exchange more water to lower your cya it would help use less bleach & testing reagents. During the day u can use a 5ml sample & every drop counts as 1ppm to conserve reagent. But for the Overnight Chlorine Loss Test be sure to use the 10ml sample - each drop = 0.5 ppm.

I see lots of algae hiding spots- skimmer, weir doors/foam, light niche (the hole the light sits in) , drain covers (there’s usually a bowl type situation under that cover that traps untold nasties) , step trim, return jets - they all need to be checked & brushed.

For a successful SLAM Process you need to continue to MAINTAIN Slam level fc for your cya until you meet ALL 3 end of slam criteria-

You are done when:

CC is 0.5 or lower;
You pass an Overnight Chlorine Loss Test
AND
the water is clear.
(Crystal Clear w/no algae dead or alive)

*Check & scrub every nook & cranny where it may hide (light niches, drain covers, ladder handrails, skimmer throats/weirs, etc.)
*Run slam level water through all water features & lines for at least a couple hours a day during the SLAM Process.
*Brush & or vac daily (this breaks up biofilms that algae uses to protect itself from chlorine)
*Backwash/clean filter when pressure rises 25%over clean pressure.

Thank you for your quick reply! I have done the overnight tests and have failed every time in my opinion. I’m continuing the SLAM until I don’t see any dead algae which is basically the only criteria I have left. I’m running low on reagent so I had to order some more.

I have removed the weir doors and checked the foam in there, they were clean. The stair seams I can’t see anything. I have checked behind the light and cleaned and did not find anything. Would you suggest removing the main drain covers? I would dive down and remove? And where else should I check? It’s literally like invisible to find what my problem is or could be. As for PH yes I understand it’s pointless to test that at this point. Those were my numbers prior to SLAM.

Oh and yes, I just cleaned filter today (cartridge) and I don’t have any water features.

 

[Mdragger88]

it sounds like the only stone unturned is the drain covers. They look like they just have two screws to remove to get them off. Be sure someone else is there incase u run into trouble. Alternatively you can use a piece of pvc to pour some liquid chlorine directly into them then brush the area really well so it doesn’t sit on your liner.
That’s Alot of drops to do the OCLT. Easy to loose count or have an error in testing. Once the dead algae subsides you can attempt an a oclt at a little lower fc.
Also for liquid chlorine- do u have a canadian tire? Apparently they offten have 10% available. It would help with the jug lugging & possibly the cost.

 

[gingrbredman]

Alternatively you can use a piece of pvc to pour some liquid chlorine directly into them then brush the area really well so it doesn’t sit on your liner

Great advice! I also read a few members who were not able to get the covers off, but got down there with a hose and a pointed nozzle to shoot water into the covers. You may see a lot of dead algae come out.

Taking the covers off is best to really get in there, but can try the nozzle blast if that isn't possible.

I know the forums say “stay the course” but I’ve literally dumped 80$ in today with little headway and this is day 3!

@Mdragger88 is right, the unintended consequences of having a CYA of 100 will require a lot more chlorine to keep it at SLAM levels. I do realize the cost of chlorine can be insane to get through this SLAM, but if you do not do it properly, the problem will not be fixed and you have to do it all over again. Stay the course is the right action, although may be financially painful at this time.

 

[wireform]

I ask did you do the diluted CYA you may be higher and not achieving slam.

 

[Mdragger88]

I ask did you do the diluted CYA you may be higher and not achieving slam.

 

[smoliakj]

I ask did you do the diluted CYA you may be higher and not achieving slam.

Yes you bet I did the diluted CYA test. I actually did it both ways. Not diluted the dot was hazy at 100 and gone at 90. Diluted gone at 50 x 2 = 100. Am I correct? Also, it’s safe to remove those drain covers on a vinyl liner? I can try blasting a hose in there first too.

 

[smoliakj]

it sounds like the only stone unturned is the drain covers. They look like they just have two screws to remove to get them off. Be sure someone else is there incase u run into trouble. Alternatively you can use a piece of pvc to pour some liquid chlorine directly into them then brush the area really well so it doesn’t sit on your liner.
That’s Alot of drops to do the OCLT. Easy to loose count or have an error in testing. Once the dead algae subsides you can attempt an a oclt at a little lower fc.
Also for liquid chlorine- do u have a canadian tire? Apparently they offten have 10% available. It would help with the jug lugging & possibly the cost.

We do have Canadian Tire.. I’ll check there and see if I can get cheaper / higher strength bleach.

 

[smoliakj]

Great advice! I also read a few members who were not able to get the covers off, but got down there with a hose and a pointed nozzle to shoot water into the covers. You may see a lot of dead algae come out.

Taking the covers off is best to really get in there, but can try the nozzle blast if that isn't possible.



@Mdragger88 is right, the unintended consequences of having a CYA of 100 will require a lot more chlorine to keep it at SLAM levels. I do realize the cost of chlorine can be insane to get through this SLAM, but if you do not do it properly, the problem will not be fixed and you have to do it all over again. Stay the course is the right action, although may be financially painful at this time.

Definitely learning this the hard way. At this point I’ll run out of reagent before I can properly complete the SLAM. I tested this morning (overnight) with cover on and had the SWCG at 100% to try to hold any level and I dropped from 39 - 28. I’m thinking my best option would be to check those drains and halt the SLAM. I’ll need to wait for more reagent and in that time can do another drain / refill to attempt to lower my CYA lower.

 

[Mdragger88]

Be sure to leave the cover off at night so the cc’s can escape.
Also - have u checked/cleaned this cover? it is now suspect #1…
What kind of cover is it?
add it’s info to your signature.

 

[smoliakj]

Be sure to leave the cover off at night so the cc’s can escape.
Also - have u checked/cleaned this cover? it is now suspect #1…
What kind of cover is it?
add it’s info to your signature.

It’s a coverpools safe-t cover… an automatic cover. I wouldn’t have a clue how to clean it (it’s motorized and in a channel so no way to get underneath it). The past two nights I covered the pool at night but I was having the same chlorine loss without it on.

I’ll add it into my signature!

 

[smoliakj]

I took off the main drain covers and light. Used a large syringe to push a bunch of bleach in the areas and scrubbed with a cloth. Didn’t seem to be anything glaring in there but did it nonetheless. Also scrubbed the steps and skimmer mouths with a bleach soaked cloth.

For draining - is it safe to assume CYA is everywhere in the pool so if I put a submersible pump in the shallow end and drain down it’s going to remove the same amount as if that pump were in the deep end?

I also checked under the cover as much as I could and it appeared rather clean. Didn’t feel scummy or anything.

 

[wireform]

For draining - is it safe to assume CYA is everywhere in the pool so if I put a submersible pump in the shallow end and drain down it’s going to remove the same amount as if that pump were in the deep end?

yes

 

[smoliakj]

yes

Thank you.

 

[smoliakj]

Thank you to all for the information, I am now holding chlorine like a mad man and my SWCG is able to hold things for the first time all pool season! I would not recommend slamming at 100 CYA however cleaning all the areas I could find as suggested by the great and knowledgeable folks here led to clean and sparkling water.

Now on to new challenges. Our fill water here has notoriously high TA. My current PH is between 7.5 and 7.8 with a TA of 190-200. My PH doesn’t rise all that fast (even with a SWCG) but I will add acid when it gets to 8.0. Problem is by the time the PH rises fast enough I usually have to add a top up to the pool which basically defeats the lowering of TA I’ve gone through.

Do I continue slowly lowering the TA over time or is this a lost cause?