MYSTERY DEBRIS/ALGAE

SLUGGO60

Active member
Jul 2, 2012
35
#1
Hello to all,

I am new to this forum so bare with me while I get up to speed. I have an 18x36 in ground vinyl liner pool which has had a problem from last season,and is still an issue this season. There is a grayish dust that collects every few days in all the crevices and seams in the liner. Shallow and deep end both have it. I can put the brush to it and it dissipates in a cloud of dust. I have shocked and brushed the pool too many times to count,vacuuming to waste the next morning,only to have it come back in a few days time. It is not yellow or green in color.It is more gray than black.

The other issue I have had since this began is that I cannot keep chlorine in the pool. The FC reading has been zero since I opened it up this year.Yesterday,I nuked it with 8 lbs of CH Shock.Today I have a free chlorine reading as posted below. I have no confidence that it will hold. Something is eating the chlorine out of this pool besides the heat(100-105 daily) . Just my opinion. I have heard that it was dust,dirt,brown algae,black algae,and numerous other things.The local talent here do nothing more than make my head hurt and cost me money.I also was gullible enough to treat for each of these things,at a substantial cost. I have had enough. The last guy I went to see told me it must be a bacteria in the water,which he had no way to test for,and I should double the shock dosage yesterday,and triple it today. Obviously,they are in the business of separating me from my cash,not trying to clear up my issue.

I have tried to post some pics of what the stuff looks like,but the BB says the files are too big. Will gladly email them to anyone who wants them. Have posted test results from this morning. I use a taylor K2005 test kit and a seven way test strip. I believe the test strips are highly inaccurate ,but until I can get some more R0013 reagent from Taylor, it is the only means of a CYA test I have. Pool supply stores do not carry that reagent. I have locked the water up twice in the last 5-6 years due to over-stabilization,so I watch the CYA closely. Any help anyone can offer will be greatly appreciated.

SLUGGO

STRIPS--TH-250PPM/TC-3PPM/FC-3PPM/PH-6.8/TA-120PPM/CYA-30-50PPM/CC-NA
K2005--TH-280PPM/TC-1.0/FC-0.5PPM/PH-7.0/TA-80PPM/CYA-NA/CC-0.5
 

SLUGGO60

Active member
Jul 2, 2012
35
#3
I had an inline chlorinator,which was removed and a salt generator plumbed in it's place. The salt system has not been started up yet.It will be ready to go in about a weeks time . I am trying to get a handle on this problem before I swap over to the salt system.The readings I posted were from this morning. Went to the local pool supply to pick up some more shock and chlorine tabs. Will bleach help me any here ? I have a bottle of clorox ready to go if need be.Will post my test results again tonight. I have had a pool for the last 15 years,and obviously I have become very complacent with how I treat the pool.Became too dependent on the chlorinator.Stopped testing every day.Any help will be appreciated.I will go to your pool school area and brush up on my pool boy duties.

Thnx,
SLUGGO
 

JohnT

Admin
Mod Squad
TFP Expert
Apr 4, 2007
9,449
SW Indiana
#5
Use bleach to raise your chlorine to the highest level you can measure, and maintain it there faithfully. It may need testing and addition once an hour for the first several hours. Once you get a handle on how fast it is being consumed, the consumption should slow. You should really run it up to 20ppm with your CYA level, but you can't test there with your kit. Allowing algae even a little foothold by letting it drop near zero will result in a pool that keeps eating chlorine. You need to kick the heck out of it, and keep kicking it when it's down Then you'll be able to hold chlorine.
 

SLUGGO60

Active member
Jul 2, 2012
35
#6
This is where I am at with the water balance :
TH-250PPM/TC-5PPM/FC-5PPM/PH-7.3/TA-120PPM/CYA-40-50PPM

Using a drop tester,and strips for a ballpark. They are much less accurate than the Taylor test kit,I will only use them for verifying the presence of chlorine.I have vacuumed the algae to waste and I am ready to shock this pool with bleach. I have a few tabs in the skimmer to hold the free chlorine level once the bleach dissipates . How much bleach is enough ? I have quite a bit ready to go.Eventually,the SWG will be wired up and I will swap it over to that source of chlorine. Until then, I am using tabs to keep it sanitized. The other question I have is how long will the pool stay at a high shock level of chlorine ? I can keep the little ones out of there for as long as it takes.With temps in the 100's every day, what would you expect ?

SLUGGO
 

SLUGGO60

Active member
Jul 2, 2012
35
#7
I forgot to mention that the pool is holding a FC level of 4/5 daily. I believe I need to shock the pool anyway because it is starting to drift to the low end,from 5-4.

SLUGGO
 

JohnT

Admin
Mod Squad
TFP Expert
Apr 4, 2007
9,449
SW Indiana
#8
You are misunderstanding the shock process. You can't let the "bleach dissipate". You have to keep testing and adding more bleach until you have all of the algae killed and your pool passes the Overnight Chlorine Loss Test. Letting it drop during the process pretty well resets the whole cleanup effort.

There are several articles in Pool School that will help you through the process:

Chlorine CYA Chart

Shocking Your Pool

Defeating Algae

Overnight FC Loss Test