I didn't really hit it with the mallet just gently tapped it just to loosen. I read several posts on this site about it and nobody seemed overly concerned about it. I'm really hoping to avoid cutting into the plumbing to get to the sand. From what I posted previously, does it appear that I have a channelling problem? I generally backwash weekly to twice a month. Would adding DE help or will it just channel through (if, indeed, I have a channel problem)?
FC level not dropping when trying to shock
- Thread starter dlwxman
- Start date
If you have to cut to get access to your filter, I would try the DE first. With that said, have you passed the OCLT and CC test yet? I would not start trying the DE until those tests pass simultaneously.
I can not see how tapping the filter would do anything. You should be inspecting and cleaning the sand yearly, so at some point you will need to cut and add unions so you can get to the sand.
You can try the DE, if it gets too the pool, you know you have problems.
You can try the DE, if it gets too the pool, you know you have problems.
Summarizing...
We're on our 4th day of slamming. Water looked much improved yesterday morning. I tried to vacuum the algae piling at the bottom of the pool. Got about 3 rows vacuumed and decided to backwash even though pressure was not elevated (it has never been elevated in almost 4 yrs). Then pool turned completely green again, maybe worse than before. I was planning to brush pool for first time yesterday when the green first started to clear. Still brushed even though water had turned green again. We've been maintaining the FC level at 26 (based on CYA level of 80 and taking the average of Pool Calculator and the Chlorine/CYA chart). Thought we might see some improvement this morning but we didn't. Trying to figure out if I'm doing anything wrong. My pH tends to drift up rather easily. I know I can't measure it with any accuracy with high FC but should I assume it has risen and add an conservatively appropriate amount of MA? Any other suggestions that might help? Or do I need another dose of POP?
We're on our 4th day of slamming. Water looked much improved yesterday morning. I tried to vacuum the algae piling at the bottom of the pool. Got about 3 rows vacuumed and decided to backwash even though pressure was not elevated (it has never been elevated in almost 4 yrs). Then pool turned completely green again, maybe worse than before. I was planning to brush pool for first time yesterday when the green first started to clear. Still brushed even though water had turned green again. We've been maintaining the FC level at 26 (based on CYA level of 80 and taking the average of Pool Calculator and the Chlorine/CYA chart). Thought we might see some improvement this morning but we didn't. Trying to figure out if I'm doing anything wrong. My pH tends to drift up rather easily. I know I can't measure it with any accuracy with high FC but should I assume it has risen and add an conservatively appropriate amount of MA? Any other suggestions that might help? Or do I need another dose of POP?
Are you running the filter 24/7? My pool took 14 days of non-stop SLAMing and filtering to clear. Do like jblizzle says. Grab some DE and pour into your skimmer with the pump running. Have someone watch the return. If you see a white plume of DE coming out of the return, then something's wrong with the filtration end. If not then you should see a rise in pressure within 15 minutes after adding the DE.
I only backwashed about 4 times during the whole process. Once 10 hours into SLAMing. Then about 2 days later. It was another 5 or 6 days after that till I needed to backwash. I have a small filter and I still only need to backwash once or twice a month depending on how much dirt gets tracked or blown into the pool.
I only backwashed about 4 times during the whole process. Once 10 hours into SLAMing. Then about 2 days later. It was another 5 or 6 days after that till I needed to backwash. I have a small filter and I still only need to backwash once or twice a month depending on how much dirt gets tracked or blown into the pool.
Improvement! Water has turned to greenish/gray. :-D Got DE today and will add it in this evening.
Note: Edited for the color
Note: Edited for the color
Personally, I wouldn't try the DE until you pass the OCLT (or are close) and have less than 0.5 ppm CC and are just trying to clear the water of dead algae.
If I decide to wait on the DE as suggested above, will the cloudiness go away on its own if, in fact, I do have a filtration problem? I'm imagining some of the heavier residual sinking to the bottom and the rest continuing to endlessly circulate around the pool and through the filter...endlessly cloudy pool. Am I off base somewhere? Would I use some floc at some point to help coagulation?
The reason to wait on DE is it does nothing to help kill the algae, and your filter will plug much faster with it in (if the filter is working correctly). Once the algae is dead, then the filter becomes important since that is what removes the remains of the dead algae.
The argument for waiting on floc is basically the same. In addition, floc can sometimes make things worse.
Bottom line, I would pass the OCLT and have CC<0.5 before adding DE. Then I would try the DE long before I would resort to floc. And if the DE didn't give steady daily improvement to water clarity, I would take the filter apart and check for issues (again long before I would personally resort to floc).
The argument for waiting on floc is basically the same. In addition, floc can sometimes make things worse.
Bottom line, I would pass the OCLT and have CC<0.5 before adding DE. Then I would try the DE long before I would resort to floc. And if the DE didn't give steady daily improvement to water clarity, I would take the filter apart and check for issues (again long before I would personally resort to floc).
I understand the DE is for improved filtering. I will wait as you suggest and see what happens. In the meantime I'll be happily SLAMing!
Passed OCLT! CC = 0! Pool looking very clear! Took some time, POP and 60+ jugs of bleach (8.25%, 121oz) but I was diligent and consistent and it worked! Planning to hold off on swimming and doing one more OCLT tonight. The key was getting the CYA measured accurately. Then we started with shock FC of 26 (average of Pool Calculator and Chlorine/CYA chart). Noticed on another thread with same CYA using a shock FC of 31 that the results seemed faster than we were getting. So we upped the level to 31 and saw a much faster improvement (although can't say for sure it was cause/effect). In the future I will plan to use the chart (hopefully will NEVER need it though). I will post a photo when I get a chance.
One question for the future: Now that I have a working chlorinator for my SWG is it OK to use that to supplement the bleach when slamming? I figure if I can save a jug of bleach here and there it might be worth it. Of course I would turn it off when doing the OCLT.
One question for the future: Now that I have a working chlorinator for my SWG is it OK to use that to supplement the bleach when slamming? I figure if I can save a jug of bleach here and there it might be worth it. Of course I would turn it off when doing the OCLT.
Nice work on clearing your pool. 
It's OK, but don't rely on it to quickly raise the FC, which is what you need to do when you SLAM and why we suggest bleach.
Understood...just using it to supplement the bleach once shock level is reached.
A big "Thank you" to everyone for their wonderful advice! :-D
A big "Thank you" to everyone for their wonderful advice! :-D
Now that have learned how to manage the pool. You should never have to SLAM the pool again. Just maintain adequate FC and the SWG will never have to be used to supplement the SLAMing process.