Question on brushing during SLAM and how to know when we are done

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T

tko

0
Apr 13, 2016
75
Portland/OR
So I'm in the middle of SLAM'ing...FC target 13, CC usually between 0 and .5, and each morning, it is around 10.5-11 (so not losing a lot overnight). Is it still eating algae? Pool is cloudy, though water looks clear when I scoop it up. We're brushing the walls (pool is 9-10ft on deep end) and as much as we can around steps, returns,etc., but I'm not sure that we are effectively getting all the algae off. The deeper we go, the less leverage and force we're able to exert during brushing. It feels pretty ineffective by the time we are brushing near the floor. I've almost fallen in a couple of times. At what point do I have to get in the pool and scrub (at what FC level is it safe to?), and how do you do it in the deep end? Do you brush the floor as well? I see a thin layer of silt, and some metal staining at the bottom, but can't brush the floor very well. What effect will that have on banishing algae?

At what level of FC loss do you declare SLAM is done? I'm not sure at this point if I keep taking it to 13, or just let the filter uncloud the water.

I added DE to help with the filtering, but am not sure how much/often to keep adding. I'm backwashing at least once a day.
 
Congratulations! You have 4 required readings! These will answer most of your questions. Please do ask any remaining or new questions after reading them. They are very thorough, but not 100%, just bring you up to a great workable knowledge faster than anything.

1. Add DE to a Sand Filter
2. SLAM Ending Requirements On Middle-ish Of This Page: SLAM
3. More information about the overnight chlorine loss test (don't skip this): OCLT
4. http://www.troublefreepool.com/threads/100385-The-Importance-of-Brushing (especially read comments #5 & 6 by pooldv and chem geek)

Lastly, don't fall in over brushing. It isn't worth the cost of a cell phone in your pocket to get that last few inches right now. After the pool is safe to go in, you can brush while in the pool very easily. You may want to consider a product like they talk about in this post called a wall whale that has a spoiler on it to create down force to hug the brush to the wall - plus maybe a pole extension. Pool dv once said that generally it is safe to swim when PH is 7.2 - 7.8, Chlorine is above minimum level for CYA level, Chlorine is below shock level for CYA level, and water is clear.

Additional brushing info highlights not from the above thread: (no need to click below links, just provided for credit and additional context/curiosity)

taken via a Richard320 comment: "The vacuum is for picking up stuff off the bottom. If there's nothing to pick up, you don't need to vacuum. Brushing is the aquatic equivalent of dusting. Stuff clings to the walls and the brush gets it off so the filter can grab it."

taken via a chem geek comment: "If you don't have returns that have circulation flowing along the walls, there can still be dead spots. It's probably even more of an issue with a pebble finish that isn't as smooth. Brushing a pool weekly is recommended for all pools."

taken from a frustratedpoolmom comment: "brushing helps minimize the risk of algae spots in areas that get poor circulation. Especially important in plaster pools or pools with surfaces where algae can grow easily. Harder for vinyl. Brushing also keeps everything stirred up so the filter can catch the particles."
 
Thank you for your response. I have actually read all of these, but I guess I need the big crayons to understand some things:

1. I am just not clear on subsequent additions, when it says you can just add "the full amount", what that actually means. The instructions say to use a pound, which seems a lot more than 1-2 cups given how light the powder is.
2. I've had nights with virtually no FC loss, but since the water isn't clear yet, and some nights, I lose 1.5, I will keep SLAMing. Once the water is clear, and I get one night with < 1ppm loss, do I call it good or should I do it over a couple of nights to be sure?
3. The link somehow got mixed up with the "brushing" link, but I did read the OCLT and am doing that nightly/daily.
4. Brushing instead of going to the gym because my arms are pretty well zapped after. That, and running the ducks out of the pool (6 mallards have decided that our pool is a good hangout).

I will check out the wall whale.

Thank you!
 
You should keep maintaining your SLAM level FC until you meet all three criteria below:

1. Water is clear (not cloudy and no visible algae, you should be able to tell if a coin is heads or tails in the deep end)
2. You pass the OCLT (overnight chlorine loss test). This means you lose 1ppm or less of FC overnight.
3. Your CC is 0.5 or less.
 
A+ on your readings :) No worries, Maybe this will help, but if not, please try to ask again.

Get up, empty skimmer basket, do 10mL FAS-DPD test very carefully swirling after each drop, write down FC, CC.
Open PoolMath on phone or computer. Make sure gallons are correct, put your new test result in NOW FC, then put your shock FC according to CYA chart in the GOAL FC box, and make sure you specify the % bleach you are using, then hit calc. It will tell you how many ounces of bleach to add right then. Pour that slowly in front of return.

If you have time, brush the the poor circulation areas (steps, return jet, skimmer basket, corners, dead walls). You can do the entire brush later, just hit the spots that cause the most problems real fast, 1-3 mins.

Go work/do daily tasks.

When come home/done (minimum 2 hrs), empty skimmer, retest FAS-DPD. Repeat PoolMath process and add required bleach to once again be at shock fc. If you have time, do full brush and check PSI on filter gauge. Clean/backwash if pressure is up 25% above clean pressure (ask if that didn't make sense). If no time, do later that day.

Before you go to bed, empty skimmer, FAS-DPD, calc, add, brush dead spots, or, if haven't yet, brush entire and psi check/clean if needed.

This is kinda like a reworded slam summary.

If PoolMath is causing you problems, see post #36 of this page where i walked someone else through it better and with a screenshot of it filled out.



Full amount comment is if you are trying to raise or lower a non-FC chem level and don't want to overshoot it in either direction, you just add like 50% or 80% of the calculated value, wait, retest, recalc, add any remaining needed. Like if you were adding acid, and wanted to do it in two small steps instead of one big pour, for extra caution.

If you have completed a perfect SLAM, your pool will use almost zero FC when the sun has set, only needing to oxidize any debris that blows into the pool and the very slow degradation over time that is negligible over 8 hours. Losing 1.5 FC between sunset and sunrise means you are killing algae, virus, bacteria, organic material, oils, etc. either in the water, on the wall, on the bottom, in the skimmer, or stuck in the filter. A completely clean/clear pool that runs an OCLT and didn't have any nature fall in it or any swimmers would lose 0 over night. That's the goal really. Only lose FC to sun, swimmer contaminants, and organic nature debris. Not to be forever battling trace algae hiding behind returns, in corners, skimmer frame, above water line, ladders, hoses, pool toys, etc. You want every last trace of algae dead and history forever. Maintain FC per CYA chart, run the pump enough, brush the dead spots, remove/vac/skim debris, clean the filter, and it just simply can't ever grow back. It's always killed in like 2 minutes of entering the pool. Chlorine is amazing when used correctly.
 
Thanks for taking the time to give this fantastic run down.

I have failed to empty/brush skimmer...makes total sense and I will do that from now on. I have a small kitchen brush and will sanitize it first. I have also been pouring bleach around the perimeter of my huge pool, then brushing to swish it. I will pour it in front of the returns from now on.

The "full amount" I am asking about is the full amount for DE. That DE link mentioned putting in DE slowly the first time, but you can put in "full amount" of DE after the first time, but I don't know what that is. And I don't think DE is a calculation in Pool Math (or my eyeballs are cloudy from staring at my water).

For a 28k-30k gallon pool (not sure exact amount as I'm unsure of the water depth and shallow to deep gradient), I have only one skimmer and that seems inadequate, so hoping to improve filtration with DE). I plan to also try to vacuum the silt from the bottom of the pool once my new pool hose comes.

Heading home ("time to test the water", "time to brush the pool" - in the same tone as"time to make the donuts"). Maybe y'all are too young to understand that reference. :D
 
Full amount of DE when adding DE to a sand filter refers to the very carefully obtained amount that raises your PSI gauge on filter by 1 PSI above the clean filter pressure starting value. If that doesn't make complete sense, you should stop using DE until you understand it better.

- - - Updated - - -

Additionally, search for deep clean sand filter. Don't do it, just read it and let us know if you think your situation/and filter may qualify for that course of action. It's imperative to not go into a deep clean prematurely, as it is easy for the unprepared to damage parts that would prevent running the filter until repaired.
 
Glad to help. As far as I understand it, deep cleaning isn't required if you are still successfully filtering water, pulling stuff out, sending it out on backwash. It just might drastically improve filtration ability to brand new performance level. If your backwashes are clearing dirty stuff from the pool, I guess you don't need a deep clean, just optional. It could become a need if the filter was unable to clean I suppose, but an alternative would just be new sand. In any case, I'm really new to sand filters, so don't you dare do anything on my word alone when it comes to sand filters. Just wanted to make you aware of that potential procedure.
 

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