When we opened our pool this spring there was a large stain in the deep end around the main drain. We regularly get a large volume of worms that enter the pool after we close it in the Fall that must be vacuumed out when we first open in the spring. We assumed the stain came from the worms and/or possibly leaves that sat in the deep end over the winter. We have rubbed Vitamin C tablets directly on the stain and none of it came off. The stain appears to have lightened since opening the pool but is still very visible. Brushing the stain does nothing to it.
We are now trying to verify if the stain is something living that can be removed by shocking the pool. We use standard store bought bleach to sanitize the pool and have attempted to keep the level above 3 ppm since opening. We believe we may have never shocked or sanitized the pool enough since opening this year to kill everything living in it. The pool has had minimal use since opening this Spring.
We have been super shocking the pool all this week to try to get an unchanged chlorine reading through the night.
Our current levels as of 7:15 am on June 10, 2010 are: (we use FAS-DPD test kit)
FC = 16.5
CC = 0.5
pH = 7.6±
Alkal = 100
CYA = 50
(Just in case it does not appear in my signature - we have 10,000 gallon in ground vinyl lined pool with sand filter)
When we tested last night after dark the FC was 19.50 and CC = 1.0
This is the best FC hold we had over the past three nights. Previous readings were FC=14 night, and 10.5 morning. FC=15 night and 7.5 morning. CC has been mostly 0.5 all week with a couple tests up to 1 ppm during rain yesterday (the way our test works, one drop of the re-agent equates to CC=0.5 so that is the minimum we can read).
Everything we read indicates that to be sure all organisms in the water are killed, the FC should drop a maximum of 1.0 ppm overnight. The question is, with this much chlorine in the pool over the past 3-4 days (8 - 19.5 ppm depending on time of day and how much bleach we added) do you think we will ever get to the point where the FC drops a maximum of 1 ppm overnight???
Any suggestions on what else to do to get rid of the stain in the deep end would be appreciated also. One thing that I still would like to do to the stain but have yet to try is rubbing it with one of the rubbing stones that we purchased at the pool supply store last year.
Once we are done with this shock process we plan to keep the FC between 4 and 6 ppm and shock only when CC gets above 1.5 or so.
Thanks for any help you can offer.
We are now trying to verify if the stain is something living that can be removed by shocking the pool. We use standard store bought bleach to sanitize the pool and have attempted to keep the level above 3 ppm since opening. We believe we may have never shocked or sanitized the pool enough since opening this year to kill everything living in it. The pool has had minimal use since opening this Spring.
We have been super shocking the pool all this week to try to get an unchanged chlorine reading through the night.
Our current levels as of 7:15 am on June 10, 2010 are: (we use FAS-DPD test kit)
FC = 16.5
CC = 0.5
pH = 7.6±
Alkal = 100
CYA = 50
(Just in case it does not appear in my signature - we have 10,000 gallon in ground vinyl lined pool with sand filter)
When we tested last night after dark the FC was 19.50 and CC = 1.0
This is the best FC hold we had over the past three nights. Previous readings were FC=14 night, and 10.5 morning. FC=15 night and 7.5 morning. CC has been mostly 0.5 all week with a couple tests up to 1 ppm during rain yesterday (the way our test works, one drop of the re-agent equates to CC=0.5 so that is the minimum we can read).
Everything we read indicates that to be sure all organisms in the water are killed, the FC should drop a maximum of 1.0 ppm overnight. The question is, with this much chlorine in the pool over the past 3-4 days (8 - 19.5 ppm depending on time of day and how much bleach we added) do you think we will ever get to the point where the FC drops a maximum of 1 ppm overnight???
Any suggestions on what else to do to get rid of the stain in the deep end would be appreciated also. One thing that I still would like to do to the stain but have yet to try is rubbing it with one of the rubbing stones that we purchased at the pool supply store last year.
Once we are done with this shock process we plan to keep the FC between 4 and 6 ppm and shock only when CC gets above 1.5 or so.
Thanks for any help you can offer.
