Slippery liner - normal?

[carlh]

I'm a new pool owner and wondering if my slippery liner is normal or something else. Almost 2 weeks ago I adjusted pH by adding borax and thought maybe the slippery feeling was due to that, but it hasn't gone away. The feeling is the same on the sides or the bottom. The liner appears to be clean, the slipperiness doesn't rub off, so I don't think there's anything growing on it. Water is very clear. Here's the data from TF100:

FC 1.5
CC 0.5
pH 7.3
TA 100
CH 200
CYA 50
Cu 0.3 (from pool store test, algaecide with Cu was added at opening)

I figure I need to shock the system to kill off the CC and raise the FC a bit. Any other advice?
TIA

 

[reebok]

you definitely need some chlorine. see the chlorine/cya chart. then I would do an overnight fc loss to see if you're losing chlorine. do you have a good test kit? have you read pool school? what chemicals are you using?

 

[carlh]

Hi Reebok, thanks for the reply. Your question about my test kit was already answered.

Neglected to mention though that I'm running an inline EZ-Chlor, running the pump about 50% of the time, and also a floater with 3" tabs. Between those two, the FC reading I reported has been maintained for a few weeks - not going up, not going down.

I've read pool school, know about trichlor and potential CYA addition, but thus far with a lot of rain and weekly backwashing the CYA level hasn't risen in the past month. As long as CYA doesn't rise, I'll keep using the EZ-Chlor and 3" tabs until they run out, then go to bleach exclusively.

But all that notwithstanding, since I don't appear to have algae growth, what else would contribute to the slippery liner?

 

[257WbyMag]

Adding borates usually changes the feel of the water to a more silky, softened type of feel. I think that this is one of the benefits of borates. Perhaps this has translated into the feeling that you now have with regard to your liner.

Like reebok said though, you should bump your FC up. An FC of 1.5 is too low of a residual for your CYA of 50 ppm. Aside from that, your numbers look pretty good.

 

[Guest]

But all that notwithstanding, since I don't appear to have algae growth, what else would contribute to the slippery liner?

You have a slippery liner. That is usually an indication of a nascent algae bloom. You also have CC and your FC is too low for your CYA-- a recipe for algae! The continued use of trichlor is going to cause your CYa to rise even higher and if you are only maintaining 1.5 ppm FC then the problems are going to keep getting worse.

If you shock the pool the problem will go away for a short time becasue you will kill the algae but it WILL return in a short time.
Your symptoms are the first signs of a pool on the brink of overstabilization. The fact that you have .3 ppm copper in the water, which is considered an active algaestatic dose, indicates that your pool is read the point of major problems unless you are going to be adding algaecide weekly (but NOT copper unless you want stains and green hair) orborates to 50 ppm. These will work for a while but eventually your pool will reach 'critical mass' as the CYA levels continue to rise. You can also do periodic drain and refills to keep your CYA in check (and for your pool as you are currently running it 50 ppm seems to be the cutoff). Finally, you can stop using the trichlor and follow the recommendations in our Pool School section of the forum (link is on every page in upper right hand corner). You Have read Pool School, haven't your?

 

[carlh]

Hi Waterbear, you do read my posts, don't you?

As I indicated, despite using trichlor my CYA levels aren't rising. I'll shock with bleach and see what it does to the slippery feeling and CC levels and report back.

 

[Guest]

Hi Waterbear, you do read my posts, don't you?
I read all of them, just don't have time to answer them all. I do work at a real job!
As I indicated, despite using trichlor my CYA levels aren't rising. I'll shock with bleach and see what it does to the slippery feeling and CC levels and report back.

They are not rising now but over time they will. It is a very rare pool that puts in the same amount of CYA that is removed by backwashing. I have seen it a few times but very rarely. In any case, your FC is way too low for your CYA level and if you crank up the amount of trichlor used you will increase the amount of CYA being added so it's a catch 22. You are going to have to add addidional unstablized chlorine to maintain the FC at 4-6 ppm to keep the pool algae free. Shocking weekly is another option but it will put your pool out of use for about a day every week and it's no guarantee that you will not get an algae bloom. Keeping the FC at the correct level for your CYA will.

 

[carlh]

Not planning to add more trichlor to increase FC levels... if the existing trichlor sources aren't enough after the shock subsides I'll augment with bleach. Don't want to mess up the perfect balance I have going on with the CYA level.

And please, do your real job first. It may be a struggle but we'll get by if you wait until after work to reply.

 

[Guest]

Not planning to add more trichlor to increase FC levels... if the existing trichlor sources aren't enough after the shock subsides I'll augment with bleach. Don't want to mess up the perfect balance I have going on with the CYA level.

And please, do your real job first. It may be a struggle but we'll get by if you wait until after work to reply.

No worries, don't go in until 3pm today so it's before work for me right now! I will check back in around Midnight when I get back home!

 

[h2ctpdjl]

I think waterbear is right on the money. I had that same slippery problem with my liner and steps last year. My sister even slipped on the steps as she was entering the water and she broke her big toe. I suspected something was wrong as it wasnt normal for my liner and steps to be slippery. Next thing I started to notice was my water began to feel "thick". I know thats a weird way to describe it, but thats exactly what it felt like. At that point, I went back to the PS and they fed me so much information, I left without buying anything and came home totally frustrated. I didnt understand the process of maintaining a pool, period. I just did what the PS told me, not understanding why. I searched the internet that same day and luckily stumbled onto the TFP website. They told me i was in the midst of an algae bloom and after following their excellent advice to read pool school and shock my pool, my pool cleared up and has been that way ever since.

 

[duraleigh]

Carl,

Just to reinforce waterbear's excellent advice, you do not have enough chlorine in your pool and I strongly suspect the slippery feel you get is from algae....whether you see it or not.

If you do the overnight FC loss test, I think you will find that something other than sunlight is consuming your FC.

 

[carlh]

OK, here's what's gone on.

About 4 days ago I shocked the pool with about 5.5 gallons of bleach and 1 lb of 73% cal-hypo. That was enough to raise the FC to 22, measured about an hour later. Left the pump running (with EZ-Chlor inline chlorinator, although that chlorine canister is nearly spent) and left a floater with 2 trichlor tabs in the pool.

About 20 hours later I brushed the sides and bottom, and vacuumed the bottom. Measured a FC level of 11 ppm and CC still 0.5.
That evening it started to rain, so I turned off the pump.

The next day it rained, pump was off all day.

About 48 hours after the 11 ppm reading, turned on the pump. This day was partly sunny. 4 hours after turning on the pump, got FC of 5 ppm and CC at 0. pH was 7.2, other readings essentially the same as my first post.

I would think the shock was strong enough to kill anything trying to grow. Remember that I've got a 0.3 copper level as well as borates in the pool (2 large boxes of 20 mule team). And my current FC reading is plenty high for the 50 CYA level.

So, what's all that done for the slippery feeling liner?
Absolutely nothing. It feels exactly the same.

Maybe a slipperly liner is just a slippery liner in this case.

 

[Guest]

I don't think you quite understand the process of shocking the pool. What you described is not really shocking to kill algae or biofilms and biofilms are much harder to kill than algae and that is what I am sure is making your liner slippery. I usually do not differentiate between them but in your case the extra info might convince you that a slippery liner is not normal.
pool-school/shocking_your_pool
You wanted me to read your posts now you gotta suffer the consequences!

 

[carlh]

For reasons I won't go into further, I don't have the ability to measure FC levels at sunrise or even hours after sunrise. So confirming zero loss of FC overnight is not available to me right now.

So you are correct, I did not follow the letter of the "how to shock your pool" law. Still, I put a pretty strong dose of FC - higher than shock level - and probably had an overnight that averaged out to the required shock level. I thought that should be good enough to notice some difference - any difference.

When I can more closely monitor the water I'll try it again.

Certainly I would think maintaining a 4+ FC level from now and remembering that I have multiple algaecidic agents in the water, should prevent anything worse than a biofilm. Would you say that using a pool with biofilm on the liner is a health hazard?

 

[carlh]

BTW, since I'm going be so careful about shocking the pool next time, TFP and poolcalculator.com have a difference of opinion about required shock level. With CYA of 50, the chlorine/CYA chart calls for 20, while poolcalculator calls for 16. So who's right?

 

[frustratedpoolmom]

They both are, the 16 may take a little longer but both will work.

 

[Guest]

The reason our recommended levels are a bit higher than the pool calculator is to provide a 'safety margin' to compensate for possible testing error or laxness in maintaining the chlorine levels.

 

[JasonLion]

To get rid of a biofilm, you need to maintain shock levels of FC for a couple of days, not just a day and a half. If you are unable to measure the overnight FC loss, you need to maintain shock level for several days longer to be sure you really got it all. It is also good to brush the entire pool daily while it is at shock level.