Ready to SLAM and I have some questions

sonoman

Active member
Dec 27, 2010
33
Santa Rosa, CA
I just received my TFTest 100 kit to replace an older Taylor K2006 because I want fresh reagents. When using the R9 dropper the drops came out faster than the other reagents or my Taylor kit R9 reagent and the drops were smaller than the other reagents or the Taylor kit R9 drops, maybe half the size. The result was it took 26 drops to measure TA, resulting in 260 but my old Taylor kit reagents took 9 drops, for a reading of 90 TA that was much closer to what I expected. Is the R9 vial in the TF100 kit different from the rest, resulting in smaller drop sizes? I don't trust the readings.

Second, I got CYA of about 110, so that needs to come down. How can lower it short of draining a lot of (expensive) water?

The pool is/was SWG but the salt cell is going bad and not generating so I was using chlorine tablets as I typically do over the winter. I got about 18 inches of rain over winter, which usually dilutes my pool chemistry.

My measurements
FC: 5.5
TC: 5.5
CH: 375
CYA: 110 (most likely due to the chlorine tablets)
TA: Taylor kit says 90, TFT 100 kit says 260
pH: 7.4
NaCl: 3000

Where do I start with the SLAM? Start dumping bleach in (assuming WalMart will sell me 16 gallons) or buy liquid chlorine from the pool store?



27k gal in-ground, pebble sheen surface, well water (soft water faucet), DE filter, salt water but SWG is not working
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
29,926
Laughlin, NV
From Total Alkalinity - Trouble Free Pool
Sometimes a static electric charge can build up on the R-0009 dropper bottle tip, causing the drops to be smaller than usual and making the test read higher than actual. You can prevent this by wipping the tip of the dropper bottle with a damp cloth or tissue before you start and after each drop.

CYA -- did you get the 110 using the dilute method?
Step 8 in CYA - Cyanuric Acid Test - Trouble Free Pool

Are you going to replace the SWCG or start using liquid chlorine?
 

sonoman

Active member
Dec 27, 2010
33
Santa Rosa, CA
Hi Marty,
I re-checked using the standard method and the 2x method described in the CYA link. The standard method fell a little below the 100 mark...it's a non-linear scale but I would estimate it about 120. The 2x method came to about the 80 mark suggesting CYA around 160.

How do I get CYA lower? In dry CA I hate to drain if I can avoid it

thanks

This morning
FC=5.5
CC 0
CH 400
TA: I continue to get different results. Using TFTest 100, I get 190-240. Using TFTest reagents then old Taylor 009 (for more consistent drops) I get 80. I have no confidence in this test
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
29,926
Laughlin, NV
At CYA of 160 you essentially need to do a full drain and refill. You can leave 10% or so of the old water if you want.
Or you can look for a Reverse Osmosis service. Will cost ~$1000 plus about 25% of your pool volume in new water.

SWCG are great. Especially here in the west where we do not close our pools. Mine makes our chlorine down to 52F water temperature so it is only off for about 8-10 weeks a year.

A SWCG that costs $500 and is replaced every 5 years is a bargain. $100 per year for your chlorine needs is hard to beat. That is about 25 gallons of 10% liquid chlorine.
 

sonoman

Active member
Dec 27, 2010
33
Santa Rosa, CA
Thanks for your help.

I am going through the stages of denial to acceptance on refilling the pool. I can't do it now because the water table is still too high and I don't want to float the pool. I can add water slowly off my well to dilute it out but it will be a slow process. I will aim for fall when the water table is lowest to flush out the CYA.

I will purchase a new T-Cell. I see you recommend 2x the size of the pool. I have been using a T-Cell 15 on my 27k gal pool...not quite 2x so should I upsize more? Do they make a bigger one? The Hayward warranty and support is horrible and they are trying to drive customers to their pool store dealers. Any recommendations on brands, pros/cons of refurbs, and where to purchase?

Also, since I will have to drain the pool, other maintenance projects come to mind. I have nasty white deposits on my tile (see photo)...my guess is calcium deposit....right at the water evaporation line that extends from a low-water point maintained during the summer by the auto-fill up to to the level of the high-water drain during the winter rainy season. Is there any way to clean the tiles? I have tried a bunch of ways and haven't found anything that works. Do I need to replace the tiles and start over? Second, the scale is clearly a by-product of the water chemistry leaving these deposits on my pool tiles. How do I prevent this from reoccurring in the future?

Thanks
 

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mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
29,926
Laughlin, NV

Read the No Drain Water Exchange as described in the article linked above.

A T15 is the largest SWCG that Hayward makes. It should be fine in your climate and you have a VS pump so running long time frames is not very expensive.
 

sonoman

Active member
Dec 27, 2010
33
Santa Rosa, CA
Good lead. I read both the link and the source article. I am on well water, but the pool fill comes post-water softener and that water is very neutral. I mention the well because I don't want to run it too hard...for the same reason we don't want to damage the pool pump. After reading the articles, I have a question on deep pump/shallow fill or shallow pump/deep fill. My fill water coming from my well is more than 20 deg cooler than my pool water, even with the solar disabled. My salt is over 2000ppm and I have the CYA problem we discussed. Even with the cooler water, should I still pump from the deep end?

Also, any thoughts on my calcium deposit post?

Thanks
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
29,926
Laughlin, NV
You are kind of one way or the other. The water temperature difference is a pretty strong factor. If your fill water is more than 20 degrees cooler, I would add in the deep end and pump from the surface.

The scale you show looks like typical calcium scale from a water not controlled using CSI. You will get some evaporite no matter what, but not that much. Best way to remove it is to hire a blasting company that uses kieserite media.
 

sonoman

Active member
Dec 27, 2010
33
Santa Rosa, CA
OK, CSI...that's one I don't remember from Pool School. How do I manage that? Is there a test for it?

I checked the temperature. The pool temp is 79 and the water from the hose is 68. I am drawing from the deep end on the east side (submersible pump cord gets me about 75% down) and filling from the steps on the west side. Why is the temp such a strong factor? I have the flows balanced at 2.5 gal/min in and out to keep the well from running too hard. I will test the CYA tonight and run the pump all night or shut down and re-start tomorrow.

The pool is turning a little green with the new well water. I added liquid chlorine shock this morning before learning i need to drain to lower my CYA. I will get the CYA to the right level then re-start the SLAM
 

sonoman

Active member
Dec 27, 2010
33
Santa Rosa, CA
Hi Marty,
I am committed now. I started pumping water out yesterday and ran the pump overnight. CYA has fallen some, from 160 to 120. When I started pumping, pool turned green and woke up to a nearly opaque brown pool. FC is still very high from when I started SLAM, pre re-fill (I know now it was a waste of good chlorine). Pool pumps are off to keep water stratified.

6am this morning I pulled water from the surface, opposite side of the pool from the inlet hose
pH: 8.2
FC: 27
CC: 0.5
CH: 350
CYA: 120 (down from 160, using the dilute method)
TA: I still don't trust the new TF100 kit for this. I tried wiping the R009 dropper down and it helped a bit, but i still get numbers in the 250 range while getting numbers in the 90 range with my old Taylor reagents. I have not put the TF100 reagent into my Taylor bottle yet

I upped the rate water enters/exits the pool and calculate it will 5 1/2 days to replace the water. That's a long time to have the pool pump off.

I told my wife we have to trust the process. Any words of encouragement or wisdom are very welcome about now

thanks
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
29,926
Laughlin, NV
Where did you take your water sample? If the system is working, the water out should be the original water characteristics and the water in should be fresh. It is not good if your water out is showing that much mixing.
 

NorCalX

Gold Supporter
Feb 3, 2011
305
Brentwood, CA
If it helps with your decision I just went through a high CYA SLAM...in 5 days I went through 24 gallons of 10% HD liquid chlorine...and my pool was crystal clear when I started

I will be here to cheer you on. I know you are about to go through a roller coaster of stress.

But yes...be patient and trust the process.
 

sonoman

Active member
Dec 27, 2010
33
Santa Rosa, CA
Thanks for the encouragement, NorCalX! Like yours, my pool was clear when I started but i was getting algae on the sides (which clouded the pool after sweep-down) and my CYA was very high. I am now pumping water into the ditch while adding new water from my well.

Marty, my fill hose is on the west side of the pool, at the steps. My pump is on the deep end on the east side, about a foot from the bottom. I have no pool pumps on. I took the sample from about 6in below the surface at the deep end, on the east side by where the pump is hanging. It could be the CYA reading was wishful thinking and within the range of error, but the level was higher than before. I told my wife we will know when to stop when the CYA is within an acceptable range, but if there is no/little mixing, how do we know when we are done?

My pool looks awful now
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
29,926
Laughlin, NV
At your low rate I suspect you will get more mixing. But your water is 'free' coming from your well.

The process is designed to use time to determine how much to change out and then you run the pool pump for several hours to mix and test.

Sounds like you have iron in your well water. Have you dealt with that before?
 

sonoman

Active member
Dec 27, 2010
33
Santa Rosa, CA
I do have some iron...the inside of my PVC pipes get stained from it. I have a chlorine injector by my well that precipitates iron out and I have no taste inside my house whereas right off my well I can taste the iron. I have a water softener and a calcite filter and the water going into the pool is off the calcite filter.

I refilled the pool maybe 10 years ago after having the plaster re-done and we filled it with trucked-in city water. That requires the pool to be empty to accept the new water from the truck, which prompted my earlier comment about having to wait to clear the CYA until the water table drops.

Yikes...now that i think about it, i used the closest hose bibb to fill the pool, which probably bypasses the water treatment for landscaping. I just re-attached the hose to the soft water hose bibb but we have maybe 4000 gallons of the untreated well water in there now...and it's really brown. I hope it doesn't cause me problems cleaning it up

My wife is asking if filling it with well water was a mistake...

We are committed now...any suggestions looking forward?