Can this test be cut in half using 5ml of water? My FC is over 20 currently during slam
FAS/DPD Test at high Slam levels
- Thread starter VOSE Okie
- Start date
To save on reagents?
Not ideal. Not as accurate but don't know the plus/minus.
See what the experts say.
If you do, I would use distilled water not tap water.
Not ideal. Not as accurate but don't know the plus/minus.
See what the experts say.
If you do, I would use distilled water not tap water.
You will decrease your precision when you do that. TFP likes all the tests to be as accurate as possible so we think it is seldom worth the pennies you save when you do that.
- Mar 5, 2020
- 2,941
- Pool Size
- 66000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Astral Viron V35
If you really need to save on reagents here - and sometimes there are legit reasons to do so, e.g you're in the middle of a SLAM and are running out of reagent and have to survive until new supplies arrive - then I'd suggest the following.
Don't just use a 5ml sample. This not only reduces the resolution to 1ppm per drop, but you will also introduce a bigger influence of getting the 5ml not quite right (compared to not getting 10ml right), and you meddle with the intended sample to drop ratio that the test is designed for.
Instead, use a larger sample and dilute that 50:50 with distilled water, mix well. Then take a 10ml sample of the diluted water, 1 drop of reagent will be 1ppm.
I think, like that the testing errors will be a little smaller compared to just taking a 5ml sample.
I wouldn't recommend that for standard testing, but I think it would be OK to keep a SLAM going until new supplies arrive. Especially if you then also increased your SLAM level by about 1ppm to make room for higher testing errors. So you'd basically pay with chlorine to save on reagent.
Don't just use a 5ml sample. This not only reduces the resolution to 1ppm per drop, but you will also introduce a bigger influence of getting the 5ml not quite right (compared to not getting 10ml right), and you meddle with the intended sample to drop ratio that the test is designed for.
Instead, use a larger sample and dilute that 50:50 with distilled water, mix well. Then take a 10ml sample of the diluted water, 1 drop of reagent will be 1ppm.
I think, like that the testing errors will be a little smaller compared to just taking a 5ml sample.
I wouldn't recommend that for standard testing, but I think it would be OK to keep a SLAM going until new supplies arrive. Especially if you then also increased your SLAM level by about 1ppm to make room for higher testing errors. So you'd basically pay with chlorine to save on reagent.
Thanks for feedback. Not trying to save money but a little low on R-0871. I should be good to complete process while I wait on a refill.
If I determine I’m in the clear, pun intended, is there a good way to decrease the FC level faster than waiting 24-48 hours to swim again?
- May 3, 2014
- 58,276
- Pool Size
- 6000
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-40
You can safely swim in a pool as long as the FC is above the minimum and at or below SLAM level based on your CYA. You must also be able to see the bottom of the pool in the deep end of the pool.
Thx. My situation is that I have a very clear pool but was failing the overnight test by a little and wanted to be better safe than sorry. So I slammed on the side of caution. Was also trying to rule out a faulty SWCG because it can’t seem to hold the recommended FC. Do I need to just accept that I’m going to have to add some liquid chlorine to assist the SWCG in the summer? Or should I not be worried about running the SWCG at 100% for 12 hours a day. First year with a pool so still trying to get this all balanced. Thx for all feedback.
- May 3, 2014
- 58,276
- Pool Size
- 6000
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-40
What SWCG do you have? Please add that to your signature.
You can run the SWCG at 100% for 24 hours per day. It does not care. It has a finite number of generating hours.
If you set the SWCG to generate 4+ ppm FC per day does that not keep your FC in target range?
You can run the SWCG at 100% for 24 hours per day. It does not care. It has a finite number of generating hours.
If you set the SWCG to generate 4+ ppm FC per day does that not keep your FC in target range?
- May 3, 2014
- 58,276
- Pool Size
- 6000
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-40
That SWCG will add 9.3 ppm FC to your pool in 24 hours. So run it 12 hours at 100% (or if you run your pumps 24 hours per day, set it at 50%) and see if that keeps your FC in range.
This max output info (9.3/24hr) might be the missing info I needed. Thx. Details. Details. 
- May 3, 2014
- 58,276
- Pool Size
- 6000
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-40
PoolMathThis max output info (9.3/24hr) might be the missing info I needed. Thx. Details. Details.
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