One Scoop of R-0870 DPD Powder?

[JPMorgan]

So..... the Taylor instructions say to add two dippers of the R-0870 DPD powder to the water sample when testing for FC. I've been wondering if one scoop will work, as the water doesn't seem to change color much when I add the second scoop. Today I did my FC test as usual, then immediately re-tested using one scoop of powder instead of two. Same result. Any reason not to use just one rounded scoop of the DPD powder and make it last a little longer?

 

[Richard320]

The huge majority of us here use a 10 ml sample and one scoop of powder when we test FC & CC. It's precise enough for us and it saves reagents.

Rule of thumb: if you added powder and it's all dissolved but for one or two dust-sized granules, you have enough.

I believe Taylor wants you to use two so you'll buy more stuff from them. Sorta like the second shampooing.

 

[jblizzle]

You can't use too much of the powder (within reason), but too little can make the end point hard to see.

If you are using 10ml of water at normal FC levels, 1 scoop should be plenty
If you are using 25ml of water a normal FC levels, 1 scoop might be enough

If you are at shock level FC with 10ml of water, probably need 2 scoops
If you are at shock level FC with 25ml of water, definitely going to need 2 scoops.

 

[wilafur]

You can't use too much of the powder (within reason), but too little can make the end point hard to see.

If you are at shock level FC with 10ml of water, probably need 2 scoops

Doh, didn't realize this. On Day 2 of SLAM and been using 1 scoop with 10ml of water.

 

[jblizzle]

Doh, didn't realize this. On Day 2 of SLAM and been using 1 scoop with 10ml of water.

You might be fine, hard to say exactly. Depends on how BIG your scoops are

 

[wilafur]

You might be fine, hard to say exactly. Depends on how BIG your scoops are

Hahaha, I am a bit frugal so they've been normal scoops, not heaping scoops. Will test FC using 2 scoops going forward.

 

[Glofton]

Not trying to side track this thread, but, I plan on SLAMing my pool this weekend. Waiting on my tf-100 test kit to arrive this week.

Please clarify for this noob....how do I need to test my FC and CC during the SLAM?

10 or 25ml? 1 or 2 scoops of powder? And multiply drops by how much?

 

[jblizzle]

Not trying to side track this thread, but, I plan on SLAMing my pool this weekend. Waiting on my
test kit to arrive this week.

How do I need to test my FC and CC?

10 or 25ml? 1 or 2 scoops of powder? And multiply drops by how much?

Always use 10ml so each drop is 0.5ppm.
2 scoops if the FC is at shock level.

 

[JPMorgan]

Thanks for all the great information. I always use the 10 ml water sample when testing for FC, so from now on it's one scoop of powder for me. Will use 2 scoops if I'm taking it up to shock level (which I haven't had to do this season). This will save a little bit of money..... may even get through one season with my 10g jar of DPD Powder . BTW.... this is my first season following the TFP method and my pool has never looked better. So glad I found this website. Great information and great help available here. I am using up the last of my Cal Hypo (left over from last season) while keeping an eye on CH and will then switch to liquid chlorine for sanitizing my pool going forward.

 

[jblizzle]

Thanks for all the great information. I always use the 10 ml water sample when testing for FC, so from now on it's one scoop of powder for me. Will use 2 scoops if I'm taking it up to shock level (which I haven't had to do this season). This will save a little bit of money..... may even get through one season with my 10g jar of DPD Powder . BTW.... this is my first season following the TFP method and my pool has never looked better. So glad I found this website. Great information and great help available here. I am using up the last of my Cal Hypo (left over from last season) while keeping an eye on CH and will then switch to liquid chlorine for sanitizing my pool going forward.

That is great to hear!!! If you have a bit of that spare coin left, consider becoming a TFP supporter so we can keep the hamsters in the back running without having to add ads to the forum

 

[#40Fan]

Anyone doing a half scoop and 5ml of water for just FC reading? I have a 10ml syringe and have been testing it with both 5 and 10ml of water and counting each drop for the 5ml as 1ppm. Getting the same results for both amounts.

 

[jblizzle]

Anyone doing a half scoop and 5ml of water for just FC reading? I have a 10ml syringe and have been testing it with both 5 and 10ml of water and counting each drop for the 5ml as 1ppm. Getting the same results for both amounts.

Well, now you are just trying to be cheap

We only suggest going to 5ml if you are in the middle of a SLAM with high CYA and thus high FC levels. It is just not precise enough.

 

[#40Fan]

6.5 FC versus 7 is close enough for the girls I go out with that work for the government.