Efficient way to test high FC without using up reagents? (43 target FC)

[achenx75]

I'm SLAMing my pool right now and since it has about a 110 CYA level, the target FC is about 43. This requires about 90 drops of reagent in my K-2006 test kit. Anyone know of a more efficient ratio? I know that at 25ml, 1 drop is 0.2 PPM and 10ml 1 drop is .5 PPM. The only other measurement is 10ml but unsure of the exact PPM multiplier. I'm sure I'm going to need to test FC quite frequently during the SLAM process and test strips only go to 10.

Edit: Read the instructions wrong! Accidentally did 25ml as 0.2PPM. I corrected it the post. But still would like to find a more efficient way using less reagents.

 

[Deb04]

You can do 5 ml of water and each drop is 1 ppm.

 

[mgtfp]

... and if you don't have a 5ml graduation on your test vial, then use a syringe.

 

[ajw22]

The smaller the sample size the greater the error. You cannot count on 43 drops of a 5 ml sample really being 43ppm.

You need to test to a higher level, maybe 50 or 55 drops, to know you have at least 43ppm.

Or get a sample of water that tests to 43 ppm with a 10ml sample and then see how many drops it takes at 5ml.

Whatever you do you will use a lot of R-0871 doing the SLAM Process at that CYA level.

Why don’t you drain your pool by 50% and lower your CYA?

 

[mgtfp]

I agree that the testing error with a 5ml sample is larger, mainly due to getting the sample size wrong (which can get improved by using a syringe). But, especially with a standard 10ml or even 25ml sample, you also need to account for a larger counting error, pretty much impossible to count 86 drops without miscounting or even getting completely lost and having to restart.

In both cases it would make sense to aim a little higher to account for testing errors. Or, as suggested, reduce CYA prior to slamming.

 

[achenx75]

The smaller the sample size the greater the error. You cannot count on 43 drops of a 5 ml sample really being 43ppm.

You need to test to a higher level, maybe 50 or 55 drops, to know you have at least 43ppm.

Or get a sample of water that tests to 43 ppm with a 10ml sample and then see how many drops it takes at 5ml.

Whatever you do you will use a lot of R-0871 doing the SLAM Process at that CYA level.

Why don’t you drain your pool by 50% and lower your CYA?

I was going to drain to lower to 60-ish but I posted on Reddit and most of the commenters said 110 is doable so I decided to spare myself the cost of a pump and try to see if I could SLAM at 110 and have the CYA burn off to a more ideal level at the end of the summer.

 

[ajw22]

I was going to drain to lower to 60-ish but I posted on Reddit and most of the commenters said 110 is doable so I decided to spare myself the cost of a pump and try to see if I could SLAM at 110 and have the CYA burn off to a more ideal level at the end of the summer.

Ok, so the folks on Reddit tell you to do it and then you come here to ask how?

Why not ask those clowns?

You will discover why we say drain the pool.

Good luck with your Reddit way. When you decide to follow TFP Methods we will support you with it.

 

[Leebo]

I was going to drain to lower to 60-ish but I posted on Reddit and most of the commenters said 110 is doable so I decided to spare myself the cost of a pump and try to see if I could SLAM at 110 and have the CYA burn off to a more ideal level at the end of the summer.

Keep in mind also that even Taylor admits their kit maxes out at 100 for the CYA so there’s a good chance your 110ppm is even higher. I agree with @ajw22 drain it.

 

[achenx75]

Ok, so the folks on Reddit tell you to do it and then you come here to ask how?

Why not ask those clowns?

You will discover why we say drain the pool.

Good luck with your Reddit way. When you decide to follow TFP Methods we will support you with it.

No need to start bashing other groups. I'm brand new to pool ownership so I'm going to make mistakes while taking information in like a sponge. Along with new home ownership, everything has been overwhelming so I'm going to slip up, but that's how people learn. I decided to try the methods that one group said while now realizing I maybe should've taken the advice of another group.

 

[IceShadow]

Unfortunately the pool care methodology you'll find here is pretty different from the methodology on the rest of the internet.

A question - how did you get to the 110 CYA result? What were your methods of getting that test result?

I've heard of people maintaining FC at target levels at high CYA of 100 or so, but I haven't heard of someone SLAMming at that level. Not to say it can't be done, but the reagent and chlorine use alone are typically a lot more expensive than exchanging out the water, especially for someone in the eastern part of the country where water is typically pretty cheap.

EDIT: OK, found on another post:

CYA reads about 110. Does that mean I need to empty half my pool to get it down to SLAM range?

Hey all, Second post here so I apologize for the lack of info. I'm a first time pool owner and trying to tackle a green pool. I decided to test all my levels before starting and realized my CYA was 100+. I performed a diluted CYA test and it was about 110. Now does this mean I need to drain...

www.troublefreepool.com

If the diluted test reads "55" then you have to round up as it's logarythmic, and you'd really be looking at 120ppm. The margin of error is going to be doubled, too, though, so it could be higher or lower. I would agree with swapping out half the water first if at all possible, or you might be setting yourself up for a really, really tough SLAM Process.

 

[ajw22]

No need to start bashing other groups.

I am a member of Reddit and don‘t view what I said as bashing.

I'm brand new to pool ownership so I'm going to make mistakes while taking information in like a sponge. Along with new home ownership, everything has been overwhelming so I'm going to slip up, but that's how people learn. I decided to try the methods that one group said while now realizing I maybe should've taken the advice of another group.

Context is always important and trying to mix and match methods rarely works. There are many different groups advocating their methods of pool care - Pool Stores; Pool Builders; Facebook; Reddit; etc. As you float between them it helps to provide the sources if you want to discuss other methods.

 

[reggiehammond]

When I first learned of the TFP methods, I tried to SLAM at 100 CYA. It's utterly impossible.
Not only does it use tons of chlorine and reagents, but even if you successfully SLAM, to maintain the needed FC to avoid algae again without a SWCG is just impossible.

I'd encourage OP to DRAIN DRAIN DRAIN - get to a better starting place and make your life easier. You'll save a lot of money because chlorine and reagents cost a whole lot more than water!

 

[achenx75]

When I first learned of the TFP methods, I tried to SLAM at 100 CYA. It's utterly impossible.
Not only does it use tons of chlorine and reagents, but even if you successfully SLAM, to maintain the needed FC to avoid algae again without a SWCG is just impossible.

I'd encourage OP to DRAIN DRAIN DRAIN - get to a better starting place and make your life easier. You'll save a lot of money because chlorine and reagents cost a whole lot more than water!

I'm in the middle of the SLAM process and yes. It's very tedious going back to Home Depot to get more chlorine. I think I'm going to throw in the towel and get a sump pump and 50 ft discharge hose soon. My water is in that hazy blue state right now. I think I'll keep it until tomorrow and see what happens.

 

[achenx75]

I am a member of Reddit and don‘t view what I said as bashing.



Context is always important and trying to mix and match methods rarely works. There are many different groups advocating their methods of pool care - Pool Stores; Pool Builders; Facebook; Reddit; etc. As you float between them it helps to provide the sources if you want to discuss other methods.

Yes, I get that now. I do wish I posted exclusively on TFP looking for answers than Reddit but oh well. What's done is done. This will help me understand pools now and how to take care of mine.

 

[IceShadow]

I'm in the middle of the SLAM process and yes. It's very tedious going back to Home Depot to get more chlorine. I think I'm going to throw in the towel and get a sump pump and 50 ft discharge hose soon. My water is in that hazy blue state right now. I think I'll keep it until tomorrow and see what happens.

What kind of pool surface do you have? We have different recommendations on how to exchange water depending on the pool surface and equipment you have.

A no-drain water exchange is the safest for all pool surfaces. It involves adding water slowly while draining water from another area of the pool slowly, with the pump off and doing as little mixing of the water as you can (avoiding any water disturbance). You can read about it here:

Draining - Further Reading

www.troublefreepool.com

 

[achenx75]

What kind of pool surface do you have? We have different recommendations on how to exchange water depending on the pool surface and equipment you have.

A no-drain water exchange is the safest for all pool surfaces. It involves adding water slowly while draining water from another area of the pool slowly, with the pump off and doing as little mixing of the water as you can (avoiding any water disturbance). You can read about it here:

Draining - Further Reading

www.troublefreepool.com

Apologies for the delayed response! I have a vinyl liner. My concern with draining is not really knowing how much I'm draining.

 

[IceShadow]

With a vinyl liner you don't want to drain down below about 18" above the shallow end to avoid the liner shifting. The weight of the water is what is holding it in place - without water the vinyl could shift, and when refilling the weight of water could actually tear it.

If you do the no-drain water exchange, you can exchange as much as you want to. You measure the incoming water speed and outgoing water speed, figure out which is lower, match it with the other one, and that speed will tell you how long to go to change out the water you want to change. If you have 100-120ppm of CYA and want to get down to 50-60ppm, you should plan to exchange out about half the water. If your water is cloudy or green and you need to SLAM, it's best to get it down to about 30ppm, so that's exchanging out about 65-75% of the water.

 

[duraleigh]

Overall Pool Water Management, much less a SLAM, is virtually impossible at or above even 90 ppm CYA. over 100 is unrealistic and I think the only way you would say, "i'ts ok" is because you have no personal experience.

So, to the reddit group, "Stop making things up".

Come over to TFP where the vast majority of our advice is from real pool owners with practical and often scientific experience.

 

[Lilypad]

Home Depot has locations that rent sump pumps for a reasonable cost, but it might be a good investment to purchase one. Try Harbor Freight or similar. I had to do a 2/3 drain twice, years ago, due to very high CYA and my, then, lack of knowledge about how it builds up by using tabs & powdered shock.

 

[achenx75]

With a vinyl liner you don't want to drain down below about 18" above the shallow end to avoid the liner shifting. The weight of the water is what is holding it in place - without water the vinyl could shift, and when refilling the weight of water could actually tear it.

If you do the no-drain water exchange, you can exchange as much as you want to. You measure the incoming water speed and outgoing water speed, figure out which is lower, match it with the other one, and that speed will tell you how long to go to change out the water you want to change. If you have 100-120ppm of CYA and want to get down to 50-60ppm, you should plan to exchange out about half the water. If your water is cloudy or green and you need to SLAM, it's best to get it down to about 30ppm, so that's exchanging out about 65-75% of the water.

Thanks for the warning about not getting under 18 inches! I was planning on draining until the shallow end was very shallow.

So I'm already in the process of draining so I'll just do a drain and refill and test again. I'll stop at around maybe 20 inches and fill it up. After that, if it's not where I want the CYA to be, I'll do the no drain exchange like you mentioned. My pool is cloudy blue right now so I'll try to get it as close to 30 ppm CYA as I can. I'm just afraid of the cost of the water but I assume it beats chlorine costs SLAMing on a high CYA pool right?