Do I need to SLAM?

[Texas Splash]

Will need to get in the pool and inspect for how to take the light cover off. I’ve never done that before.

But only if it's one of those standard (large) halogen type lights with the hollow niche behind it. If it's a smaller LED or perhaps large LED with no niche, you probably don't need to mess with it. If you aren't sure, post some pics of the light later and we'll see if we can help.

 

[mc2005h]

But only if it's one of those standard (large) halogen type lights with the hollow niche behind it. If it's a smaller LED or perhaps large LED with no niche, you probably don't need to mess with it. If you aren't sure, post some pics of the light later and we'll see if we can help.

I took it out on Saturday and there was so much algae behind it. Thanks for the tip! I am expecting today to be my last day of slam. This morning before sunrise I had 15.5 FC, 0.5 CC and no algae. Trouble was I added chlorine at 7:40 last night and when I measured FC at 8:30 it was 17 instead of my target of 16 so I wasn’t confident in my FC drop

Going to make sure tonight I add last dose of chlorine around 6 so it has plenty of time to circulate before I get the post sunset FC reading

 

[Texas Splash]

I took it out on Saturday and there was so much algae behind it. Thanks for the tip!

 

[mc2005h]

At 6:30 I was testing at 15.5 FC. Added 15 oz of chlorine per the app. I’m now testing at 18.5 at 8:40 pm. This is the second night where my FC seems much higher than expected after sunset. Am I doing something wrong?

 

[PoolStored]

Your pool volume is off in pool math.

Since you overshot, use effects of adding. Put in before and after FC, what you added and how much. Reduce pool volume until pool math results match the FC increase.

Then use that volume going forward.

 

[mc2005h]

Your pool volume is off in pool math.

Since you overshot, use effects of adding. Put in before and after FC, what you added and how much. Reduce pool volume until pool math results match the FC increase.

Then use that volume going forward.

Hmm, that does make sense. My FC went up by 3 ppm with just 15 fl oz. I will try testing for a third time….

 

[PoolStored]

Clean your test vial with alcohol and dry, then retest.
When you test, hold bottle vertical. Squeeze VERY lightly, let the drop form and drop under its own weight. Likely testing error.

 

[mc2005h]

Hmm, that does make sense. My FC went up by 3 ppm with just 15 fl oz. I will try testing for a third time….

Clean your test vial with alcohol and dry, then retest.
When you test, hold bottle vertical. Squeeze VERY lightly, let the drop form and drop under its own weight. Likely testing error.

Thanks, did that and got 17 this time. Will rinse with alcohol again now and rest same way in the morning. Thanks.

 

[mc2005h]

Failed OCLT. Dropped 3 I’ve been vacuuming daily but not brushing the walls. I’m going to start doing that twice a day.

I hosed down my DE filter cartridge on June 19. Should I consider a deep clean if I don’t pass in a couple days? If so is there a cleaner you recommend?

 

[Texas Splash]

Should I consider a deep clean if I don’t pass in a couple days?

As long as the filter is capturing dead algae, it's working fine. No need to do a total strip of DE on the grids IMO. Certainly your call though. The FC drop overnight isn't from the filter though. That's the dead stuff. There's still live algae in the pool. You had a great find behind the light yesterday, so perhaps there was more than you realized and it's still being killed in the water.

 

[HermanTX]

I hosed down my DE filter cartridge on June 19. Should I consider a deep clean if I don’t pass in a couple days? If so is there a cleaner you recommend?

It is recommended to always monitor filter pressure, if it exceeds 25% of the clean filter pressure then backwash or clean it.
Always check at the same pump speed to compare properly.

Backwashing should suffice for your need now but a deep clean is always helpful. Suggest that you do that once the OCLT is passed so you know that all the dead algae is captured.

 

[mc2005h]

I passed OCLT!! FC dropped 0.5, 0 CC, no algae. Thank you!!!

If my pressure is still <25% higher, should I backwash now or wait?

When FC gets down to 5, should I resume using a floater with 5 bioguard silk pucks? Or do I no longer need that if I’m measuring FC and using liquid chlorine every few days?

 

[Texas Splash]

backwash now or wait?

You can wait.

When FC gets down to 5, should I resume using a floater with 5 bioguard silk pucks? Or do I no longer need that if I’m measuring FC and using liquid chlorine every few days?

I would leave the pucks alone. Stick to liquid chlorine. About the FC, always be sure to keep it in the ideal zone as noted on the FC/CYA Levels or the chart below. That's key to avoid algae. Ideally, test the FC everyday or at a minimum every 2 days if you have to and only if your FC shows a pattern of holding very well. You want the FC in that ideal zone and never want the FC to fall below that minimum number based on your current CYA.

Congrats on passing the OCLT!

 

[HermanTX]

If my pressure is still <25% higher, should I backwash now or wait?

If it was me, I would backwash to remove all dead algae.
I do not know what is in bioguard pucks but be weary of unknown ingredients. Some pucks have blue specs in them and I would definitely avoid those.

 

[mc2005h]

You can wait.


I would leave the pucks alone. Stick to liquid chlorine. About the FC, always be sure to keep it in the ideal zone as noted on the FC/CYA Levels or the chart below. That's key to avoid algae. Ideally, test the FC everyday or at a minimum every 2 days if you have to and only if your FC shows a pattern of holding very well. You want the FC in that ideal zone and never want the FC to fall below that minimum number based on your current CYA.

Congrats on passing the OCLT!

one last question - I have a dolphin cleaner. At 40 CYA, the 5-7 is still ok even though the stated limit for the dolphin is 4 ppm? I looked at some other threads and I think so but just want to double check!

Really appreciate the help of this community. I feel so much more confident about managing my pool!

 

[PoolStored]

You are fine. Mine stays in 24x7, CYA of 90 and FC of 9-12.

 

[HermanTX]

Really appreciate the help of this community. I feel so much more confident about managing my pool!

The forum is manned by volunteers that answers questions and provide guidance. Keeping the website highly functional with the latest technology is key to making the forum workable and enjoyable. Please consider and Become a TFP Supporter

 

[mc2005h]

Things have been going well. Usually losing 2 ppm FC every 24 hours, sometimes 2.5 when it’s super hot out. Topping up nightly with liquid chlorine to get to 5 ppm (at 40 CYA).

However, I’ll be going away for 7 days / nights soon and don’t have someone who can care for pool. Should I just bring to slam levels and hope for the best or is this a scenario where I might want to use the bioguard silk picks in a floater while I’m gone?

 

[greenpoolboy]

Hello! I'm very excited to join this community. I could really use your advice!

I'm a relatively new pool owner (this summer is my second full season). I live in CT and have an in-ground pool. 20x40, about 24K gallons. Chlorine, not salt. Using FiberClear in my filter. I shock with HTH advanced cal-hypo (2 bags a week) and I have 4 tablets of bioguard silk in the floater plus one in the skimmer.

My pool is crystal clear, however, whenever I shock the pool and run the filter once a week at night, I wake up to find clumps of yellowish "dust" at the bottom of the pool. These clumps are mostly concentrated at the deep end, though smaller piles can be found in other areas of the pool. I've been vacuuming these piles to waste.

On Monday June 17th (after having added 2 bags of shock on Saturday night), I went to the local pool store and told them what was happening. We did a water test and here are the results:
Free Chlorine 0.09
Total Chlorine 0.15
Combined Chlorine 0.06
pH 7.6
Alkalinity 73
Adjusted Alkalinity 76
Hardness 207
Cyanuric Acid 8
Iron 0.10
Copper 0
Phosphate 0

The store recommended I add a Phosphate reducer (just in case, even though the levels were 0) and Pool Enzyme, then take out the filter and clean it, vacuum pool to waste, then add 4 bags of shock. I had been reading this forum before going to the store and knew I shouldn't have bought anything, but I caved, spent the $50 dollars and followed the steps. I added the Phosphate reducer and Enzyme monday evening, cleaned filter/vacuumed and topped up water wednesday afternoon, shocked Wednesday evening, and then on Thursday vacuumed to waste the dust that formed again after shocking and topped up the water again. I went to the pool store today (friday). Here are the results

Free Chlorine 0.28
Total Chlorine 0.34
Combined Chlorine 0.06
pH 7.4
Alkalinity 76
Adjusted Alkalinity 73
Hardness 246
Cyanuric Acid 13
Iron 0.3
Copper 0.2
Phosphate 0

While my chlorine levels are up a bit, they are still low. The store suggested I buy zip chlor and add it tonight, but I declined because I wanted to get this group's advice first.

To reiterate, the water is still crystal clear. The only concern I have is why there seems to be dead algae after every shock treatment and why I can't get my chlorine levels to the normal range despite shocking and using expensive floater tablets. I realize now that my frequent vacuuming to waste and topping up the pool (~500 gallons a day twice this week), might also sending out some of the chemicals I added and contributing to the problem... I should probably be vacuuming the dust to filter and then backwashing.

Should I go the zip chlor route or do you think SLAM is appropriate for my situation? Ready to buy the TF Pro if you think I need to SLAM.

Thank you!!

The pool store always wants to sell you stuff you don’t need. Like selling flocculant because the water is cloudy when you need chlorine. Or selling you phosphate remover when you need chlorine, or selling you algeacide when you need chlorine. . .

 

[HermanTX]

Things have been going well. Usually losing 2 ppm FC every 24 hours, sometimes 2.5 when it’s super hot out. Topping up nightly with liquid chlorine to get to 5 ppm (at 40 CYA).

However, I’ll be going away for 7 days / nights soon and don’t have someone who can care for pool. Should I just bring to slam levels and hope for the best or is this a scenario where I might want to use the bioguard silk picks in a floater while I’m gone?

SLAM level for 40 CYA is 16ppm FC. Over 4 days you will lose 10ppm leaving you at 6 where you should be at ongoing basis.
Do you have anyone that could come by on day 3 or 4 to add more LC? Each gallon of 10% LC will raise FC by 4.2ppm so you need minimum 2 gallons on day 4.
Each chlorine puck is 8oz which adds 2.3ppm FC however that is fully dissolved. It may take days or even a week to dissolve each of them
You can add some pucks to a floater as a backup but focus on use of LC.