Slam Time in Louisiana

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E

Earlybird

0
Jun 9, 2015
25
Baton Rouge, LA
This is Earl from Baton Rouge, LA. I recently bought a new home with a pool (see signature) and began to geek out on pool chemistry at TFP.com. I also need to give a shout out to Gilbee for helping me out via text messages so far. Long story short; The previous owner used dichlor pucks, I drained and replaced to reduce CYA from ~200 ppm to 45 ppm. I fed a little 10% liquid chlorine into the pool while I did this to keep if from looking like a hand grenade on bourbon street (green drink). My current results are as follows:

FC = 1.2 ppm
CC = 0.2 ppm
Ph = 8 (Went up from 7 during drain/replace)
TA = 150 (Went up with D/R also)
CH = 140 ppm (went down from 350 during D/R - We have soft water and I used a garden hose)
CYA = 45

I added the appropriate amount of Muriatic Acid a few hours ago to get my Ph in line before I start slamming. Pool Math says I need to achieve and maintain a TC of 18 PPM. I'll start this evening if a Ph test give me my goal of 7.2. I'll try to keep a photo log for y'all. I'll take care of the CH after the SLAM. If there's something I'm missing, please let me know. Pic #1 is included.
SLAM 1.jpg
 
Looking forward to following your progression as we are in similar situations and climates. Are those rocks a water feature? How are you planning on tackling them?
 
One thing Earl, you need to test and add as often as you can during the beginning phases of a SLAM. The MAINTAIN is really (IMO) the most important part. I would suggest around every 2 hrs, until it really starts to hold, then you can stretch it out a bit. Your goal is to not let it get LOWER than the 18ppm you mentioned. You might even try to target a little higher just to be sure.
 
Update:

Half way through the SLAM I realized that there was a hairline crack in the sand filter. Therefore, I halted the SLAM for a few weeks while I worked with the home warranty company to get a replacement. I added liquid chlorine in smaller amounts to stave off any potential algae issues. Once the new filter was installed, I started over. I'm now on day three of the new SLAM and the water is looking good. Last night the FC dropped just over 2 ppm so I'm moving forward. I've tried to be more diligent with brushing the plaster to get me over the edge. When I retested it became evident that my CYA had gone from off the chart to near zero subsequent to draining and refilling my pool. I've since used stabilizer to get it up to 45 ppm. I'm maintaining SLAM levels at 18 ppm and adding a little more during the day to extend the duration (due to extreme sunlight). Everything looks great, but the only issue is the dust plumes that I have at the bottom of the pool when brushing. The plaster surface was degraded when we bought the house, but we're trying to get a year or two out of the pool before refinishing the surface. My test results are as follows:

FC - Maintaining around 20 ppm
CC - zero to 0.5
Ph - Dropped to 7.2 before SLAM. Haven't tested since.
TA - Was 170 pre-SLAM
CH - 90 ppm - Will address post-SLAM
CYA - Adjusted from near zero to 45.

I'm waiting until the SLAM is completed before using the new Dolphin Z5. Hopefully this will help with the dust. All comments or suggestions are welcome. Thanks for all the help so far.
 
If you have a main drain I suggest leaving it open during the slam.

That will help clear the water much faster. After brushing during a mustard slam my water was
like milk. with the main drain open and pump running 24/7 it would clear completely within 3 days.

I know about that dust cloud brushing on the floor, my pool has very old worn plaster and was painted and it's old old paint
so that doesn't help lol.
 
I already leave the drain open. I'm not so much concerned with the plume itself. It clears up fairly quickly. I'm more concerned with algae or organics hiding within the granular material and prolonging the SLAM process. I plan on trying to manually vacuum some of it this afternoon. Eventually we'll get the pool resurfaced and that problem will be removed. I'm sure the lowered CH level resulting from the drain/refill doesn't help.
 

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Ok guys. Here is where I'm at. I need a judgement call from the experts:

I've been SLAMing for almost three weeks now, but a sand filter crack and trips out of town have got in the way. Over the last five days I've been sticking to the SLAM regiment very well. I started by running a full test, lowering my Ph to 7.2 and began adding liquid chlorine on a regular basis. Here are the baseline results:

FC - I've been keeping it in the 18 to 25 ppm range as consistently as possible. I test 3 to 4 times a day as my schedule permits.
CC - Has been 0 to 0.5 every time I test.
Ph - Dropped it to 7.2 before beginning the SLAM and haven't tested since.
Ch - Was 90 the last time I tested it. Will address it post-SLAM.
CYA - When I bought the house a month ago. It was off the charts - I drained/refilled and got it down to 45. Subsequently, levels fell down to below 30 due to rain. I've raised it back to 45 concurrently with the SLAM.

Here is the judgement call part - I've been following the SLAM process just as specified in Pool School. After several days I have now seen a drop in FC of exactly 1 ppm two evenings in a row. It should be noted that this is south Louisiana and temperatures are very high (triple digits during the day) and I am evaluating the OTCL over a 9-hour period (8:30 pm to 5:30 AM). I've seen previous posts state that a OTCL evaluation period of 4 or greater is sufficient. It should also be noted that to preserve reagents I'm using a 10 ml sample and two scoops of powder when testing FC. Does this lighten the accuracy to a point that I should consider this?

Based on the above information, am I at a stopping point in the SLAM? The water is crystal clear and the CC levels are fine. My kids have yet to swim in the pool, but they are chomping at the bit to get in and my wife is loosing her patience with the process. And while some of it was my schedule, the cost of the slam is getting high.

The only hesitation I have about stopping the SLAM is that I still have dust that kicks up when I brush the pool. I have a Dolphin robot, but I'm hesitant to use it during high FC levels. My pole vacuum does not work very well. I was planning on trying to remove the dust post-SLAM with the Dolphin.

Thanks for y'alls advice so far.
 
you could let the FC drop to just below SLAM for one test period, and let them swim!! then bump it right back up after the fun is over. At this point it wouldn't kill all the work you have put in. Also, you might want to try looking up about using a little DE in your filter to give the water that final sparkle. I would post the link but I'm not on my regular computer today.

- - - Updated - - -

also, SLAM level FC is not really that high. The CYA is buffering it remember? I expect that your cleaner will be just fine. If you want an idea of high look up the instructions for mustard algae.
 
Another update. The hits just keep on coming......

i concluded the SLAM and allowed my FC levels to drop down to the appropriate levels for my CYA (45 ppm - ~7 ppm). I also stabilized my other parameters in the following manner:

Increased CH by adding hardener
Decreased Ph by adding muratic acid (over shot this in an attempt to reduce TA)

Here is where the fun begins. First, I noticed some small patches of what looked like algae in a spot the it was previously located before the SLAM. It was small and very hard to scrub off. All spots show up in the corners between the pool bottom and the wall or a similar place on the steps on the same side of the pool. Second, while my overnight FC reductions were stabilized right at 1 ppm, I've noticed extreme drops during the day. I decided to test CYA again and for the second time in this 3-week process I saw a significant drop in CYA (from 45 to below 30 within a day). I have an automatic float switch that adds city water to the pool when the water level dips less than an inch. At first I attributed the CYA loss to this. Well that broke five days ago so now I've been watching the water levels dip (approximately 3 inches in five days). Also, I have received some rain, but IMO, not enough to warrant a CYA drop.

Here are my latest test results after the overnight period:

FC - 5.5 (dropped 1 ppm from the previous afternoon which is consistent with previous overnight drops).
CC - 0. This has remained steady for awhile now, but up until yesterday I had been maintaining above or close to SLAM-level FC with clear water and no signs of algae.
Ph - Started at 7.8, but I worked it down to 7.2 - I was hoping to let the waterfall bring this up while maintaining a lowered TA.
TA - Started at 140 and I worked it down to 120 via the process described above. I was trying to get it sufficiently low enough to achieve an optimal CSI.
CH - Increased it from 70 to 220 in 24 hours.
CYA - Dropped from 45 to below 30 (barely off the K-2006 meter) in 24 hours.

A few notes:

The pool surface is gunite and old. there are portions of the surface that have been chipped away. There is also a white pasty film I can remove with my fingernails. I'm not sure if this is paint or just degraded plaster. When I conducted my original drain and replace, I added a bunch of city water. City water here is very soft and has a TA of 200. That resulted in low CH levels during the slam process. I'm sure that did not help the already-degraded surface. A chalky dust plume kicks up every time I rake for leaves or scrub. I figured it was a combination of dead algae, dirt, and plaster material. During the SLAM my FC dropped below slam-level for a day because I had to go out of town. Therefore, I decided to use my new Dolphin to clean the surface of the pool to remove some of this dusty material. I did not want to use my new equipment in elevated FC levels. The robot grabbed a bunch of the pasty white material each time. I had purchased some DE and was planning on using it today along with the dolphin to remedy some of this.

The pool has a rather large cascading water fall that quickly aerates the pool and increases Ph (see pictures in previous posts).

There are rock features all along the edge and side of the pool (see pictures in previous posts). If it was not for those I'd be barking up the SWG tree. They look nice, but they present many hidden opportunities for hidden organics.

There are numerous small plants located along the pool that keep me busy with the net.

The previous owner planted a crape mrytle tree just to the west of the pool which is driving me crazy. I've kept the pool clean of debris however.

I removed the two light casings and scrubbed inside them during the slam. I also scrubbed under the rock features as best I could. I still feel I could have scrubbed more on the bottom in the deep end by it wasn't time feasible and is difficult from the surface.

The sand filter was replaced a few weeks ago and after initial increases in pressure and subsequent backwashing, began to operate at consistent pressure levels during the SLAM.

The water has never been green since I began SLAMing but it does get cloudy from kicking up the plume. It got really cloudy the one time I ran the Dolphin. But toward the end it was crystal clear unless I kicked up the plume.

The only indications of algae I've ever seen have been small patches in the corners or on the steps (before SLAMing). It was green spots or patches.

We've had a few weeks of triple-digit heat in South Louisiana.

It seems the most plausible possabilities here are:

1) The SLAM was not carried out long enough and therefore needs to be redone
2) I have Mustard Algae or an ammonia issue that would require SLAMing at a greater level. This could also cause the CYA loss.
3) I have a leak causing the CYA loss. I plan on conducting the bucket test.
4) While maintaining a CC of 0 (for now), I'm overreacting to the small algae spots and need to concentrate on the CYA issue.

I've always heard the issues associated with owning a pool and I knew it would require extra work, but it's starting to disrupt my ability to be a dad or be at work. I know by choosing to use the TFP method that additional responsibilities are required on the front end and I accept that. I could just toss hockey pucks in there and cut the kids loose to go swim, but I've set the bar higher than that. I can no longer keep my kids out of the pool so any significant work will need to happen after this weekend.

Please let me know what y'all think. I've learned a bunch in the last three weeks, but I'm still a relative pool virgin.

Thanks in advance.
 
A leak would explain most everything you saw chemistry-wise. You were consistently seeing a loss of 1 FC overnight. This is probably due to your water being diluted by the auto-fill. This is also a viable reason for why you're losing CYA.
 
JV. The only caveat to that is that the autofill has been deactivated for five days. During that time I was seeing 1 ppm reductions in FC overnight. My water level has dropped about 3 inches in that time and I have a large waterfall. I have not added water during that time. I'll conduct the test to verify. Thanks for the reply.

- - - Updated - - -

Duraleigh - I'm going to knock that out soon. Does the pump need to be turned off during the test? I have a bunch of kids coming over this afternoon. If so, I may need to wait until Monday. Thanks for the reply.
 
When I did a mustard slam in july my cya went from 70 to 35.

Chemgeek mentioned that it is possible if certain conditions exist in your water where the slam levels oxidize some CYA.

If your pool is uncovered (should be for slam) and it's warm water and roasting sun all day, you will lose water.
I lose about 1 inch a week in full sun weeks but nothing lost when the solar cover is on.

I would just keep sweeping the floor once or twice a day and running the pump 24/7. most of that dust/dead algae
should dissipate after doing it for a few days.
 
Earlybird said:
Duraleigh - I'm going to knock that out soon. Does the pump need to be turned off during the test? I have a bunch of kids coming over this afternoon. If so, I may need to wait until Monday. Thanks for the reply.
Click to expand...

I think the issue with doing it with the pump on is that it can show a leak that may be in the plumbing instead of in the pool itself...at this point, I'd say use the pump as normal to determine whether you have a leak or evaproration, since that will be how things will normally be running, and if you see evidence of a leak, redo the test with the pump gear off if you think it's necessary. If you have a leak, you can let it leak below the skimmers and returns to see if it stops which may point to either a main drain plumbing leak or a crack in the pool shell (unlikely). if it stops after it leaks below those points, then it's in the plumbing, and you can troubleshoot yourself up to a point before you may end up better off getting someone out to pressure test the pipes, but at that point you at least have some direction of where to look.


Now if you do a bucket test and the kids kick over the bucket, splash water in, or pull water out, I think you can see how that might be problematic.
 
If there is a water leak, then the CH would also drop unless the fill water were high in CH or there were a lot of evaporation and refill (not just leak and refill). As for CYA and a SLAM, I'd expect at least 5-7 ppm CYA per week drop based on a 2-3 ppm CYA per month drop from normal chlorine oxidation of CYA at minimum FC/CYA levels. This is because regular SLAM levels have 10 times the active chlorine as minimum FC/CYA levels. The loss may be higher if the pH rises a lot since the chlorine oxidation of CYA occurs faster at higher pH. Nevertheless, that would't be 45 to 30 in 24 hours.
 

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