I can't be the only one with this issue

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Puppiesonacid

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May 11, 2016
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Maybe no one tests around different areas of the pool, or maybe I just stink at doing the FC test in general....

One morning after letting the FC drop so I can test PH i came up with FC 6 Figure I do the test right, but I was like, that is way to low... I tested the same spot again. Got an FC of 8 which is where it should have been.

Tested the other side of the pool and got FC 10.

Today Tested one spot. got FC 8. I was like, this is wrong... Tested another spot after running the pump for 20 mins... after it sitting all night not being on, and got an FC 11.

So either my pool is just weird, or it has the worst circulation ever. Or i really suck at doing the FC test. I have the speed stirrer... :) and CYA of 100 for those questioning the FC :)
 
A water sample for testing should be collected after the pump has been running for at least 20-30 minutes. When doing this, I've collected water samples from various areas and haven't noticed any outlying results.
 
Sounds like circulation to me, throw a ping pong ball or empty plastic soda bottle in and see what is does.. :)
 
FC is FC period. It cannot go up unless you bring it up. It will ALWAYS go down....how fast depends on a lot of factors.

Since those facts are pretty absolute, operator error is usually the cause.

Do you understand exactly at what drop of R-0871 the test has ended?
 
Puppiesonacid said:
Maybe no one tests around different areas of the pool, or maybe I just stink at doing the FC test in general....

One morning after letting the FC drop so I can test PH i came up with FC 6 Figure I do the test right, but I was like, that is way to low... I tested the same spot again. Got an FC of 8 which is where it should have been.

Tested the other side of the pool and got FC 10.

Today Tested one spot. got FC 8. I was like, this is wrong... Tested another spot after running the pump for 20 mins... after it sitting all night not being on, and got an FC 11.

So either my pool is just weird, or it has the worst circulation ever. Or i really suck at doing the FC test.
Click to expand...
It's most likely a combination of poor circulation issues and user error.

When you test FC, are you certain you are using a consistent sample size, and holding the R-871 bottle as vertical as possible and allowing the drop to naturally form & release from the dropper tip? I count my drops like I count my seconds, 1-one thousand, 2-one thousand, etc to try and maintain a 1 drop per second rate. I also use the Sample Sizer and Speedstir, which helps to remain consistant with my testing.

Dom
 
duraleigh said:
FC is FC period. It cannot go up unless you bring it up. It will ALWAYS go down....how fast depends on a lot of factors.

Since those facts are pretty absolute, operator error is usually the cause.

Do you understand exactly at what drop of R-0871 the test has ended?
Click to expand...

When it is totally clear.

I do let the drops fall, but sometimes it stalls so i squeeze a little bit. I do have the stirrer.. cause i stink at doing it myself without..
 
When it is totally clear.
Click to expand...
Pretty close.. You continue to add drops until the LAST drop you add makes no further color change. Then you subtract that drop.

Hold the bottle vertically and allow the drop to fall off the tip each time. The more you do it, the easier it gets.
 
Some things you can do to ensure you get consistent results are to pick one location and depth to collect the test sample from. For me its about 3 feet away from the return, elbow deep. When conducting the test, make sure the reagent bottle is completely vertical and allow the drop to form and drop off the tip freely with minimal pressure to ensure consistent drop size. Tilt the reagent bottle horizontal between drops while you swirl the sample being tested. Always draw the sample after the pump has been running at least 10 minutes.

You can check your circulation with a few ping pong balls. Just drop them in at different spots in the pool with the pump running and see how they circulate. Adjust your returns to direct flow to any dead areas.
 
duraleigh said:
Pretty close.. You continue to add drops until the LAST drop you add makes no further color change. Then you subtract that drop.

Hold the bottle vertically and allow the drop to fall off the tip each time. The more you do it, the easier it gets.
Click to expand...

I try to do that vertical thing, but they really do just stop after a few drops from coming out on their own.

And I will remember that. Maybe my clear isn't what I think it is.

- - - Updated - - -

zea3 said:
Some things you can do to ensure you get consistent results are to pick one location and depth to collect the test sample from. For me its about 3 feet away from the return, elbow deep. When conducting the test, make sure the reagent bottle is completely vertical and allow the drop to form and drop off the tip freely with minimal pressure to ensure consistent drop size. Tilt the reagent bottle horizontal between drops while you swirl the sample being tested. Always draw the sample after the pump has been running at least 10 minutes.

You can check your circulation with a few ping pong balls. Just drop them in at different spots in the pool with the pump running and see how they circulate. Adjust your returns to direct flow to any dead areas.
Click to expand...

Would be nice to adjust the returns, but they are just PVC pipe shooting back into the pool at 3 spots on the same side 8 feet apart
 
Just tried again and got 11... after adding half a gallon of bleach 20 mins or so ago with pump running. I have to go buy some ping pong balls. it is meant to flow around as in counter clock wise, so all the returns push right and push the water around length wise.

I know when i sit in a float it works like this as it is sort of like a lazy river i go slowly around and around. i got a variable speed pump, so i guess i am not running it as fully as a 2hp used to run, though doing the math at 1400 to 1500 watts would be equivalent.

just looked up returns on amazon... go figure, I can put stuff in the pipe... guess these people really were freaking lazy in the end of their divorce and got rid of things as i never seen them laying around, or they ever had them
 

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they are eyeballs and will bring your pressure up depending on what size you get, with 2, 3/4 inch eyeballs on my returns on high I get 15 PSI... with 1 eyeball and my sprinkler/waterfall i get 10 PSI :)
 
duraleigh said:
Pretty close.. You continue to add drops until the LAST drop you add makes no further color change. Then you subtract that drop.
Click to expand...

I know this is the appropriate method for titration tests of TA and Calcium Hardness where the test is over at that point. But with the FAS/DPD if you continue on to test for CC (adding 5 drops of R-0003, see if pink returns, then titrate once again with R-0871 to once again return to clear) wouldn't you be one drop over already when doing this part of the test and possibly get a 0 CC reading when you may indeed have CC's?

An example may be clearer... Say I am using a 10ml sample:
- One scoop powder - solution is pink
- 10th drop of R-0871 turn solution clear so I STOP and Record FC as 5.0
- add 5 drops of R-0003 and solution turns slight pink
- add 1 drop of R-0871 and solution turns clear - Record CC as .5
In example above a TOTAL of 11 drops of R-0871 are in the vial at the end of test.

Now do SAME test with the "LAST drop makes no further change" method (changes in italics):
- One scoop powder - solution is pink
- 10th drop of R-0871 turn solution clear. On 11th drop the is no further change, so I subtract that and - Record FC as 5.0
- add 5 drops of R-0003 and solution does Not turn Pink
- No need to titrate so record CC as 0.0
In this example a TOTAL of 11 drops of R-0871 are already in the vial at the beginning of test, hence the reason my R-0003 never turned solution back to pink

One method give me 0.5 CC, the other gives me 0.0

Said in other words, if I always go 1 drop over and subtract it out, then won't I always already be "1 drop into" my CC titration prematurely?
 
I can't figure it out... I am quite a perfectionist when doing the test, as much as you can be anyways, and still come up with 2 different numbers in different spots. this was after the pump was running for an hour before i got home from work.

I am sure it has to do with me, or my pool is just stupid. :) I just can't think of any other way to do it... i even use 2 scoops of powder both times, get the line the same height as best i can... and use the speed stirrer... let the drops drop themselves when they will, or very very lightly squeeze till they come out.

got 8 in one part near the returns and 9.5 away from them... getting water from about elbows length in both places
 
Make sure you have the ribbed tip inside. I just bought a refill and it didn't have it. I read an earlier thread about this problem and swapped the old bottles tip on the new bottle. I don't think the drops should be coming out by them selves without a little pressure to the bottle.
 
wjr75 said:
Make sure you have the ribbed tip inside. I just bought a refill and it didn't have it. I read an earlier thread about this problem and swapped the old bottles tip on the new bottle. I don't think the drops should be coming out by them selves without a little pressure to the bottle.
Click to expand...

It is the right bottle tip. The first one I got was right, the second one was wrong, so when the first was empty i switched them.

Maybe it is the amount of powder... almost wish the spoon was bigger... and more precise.

Editing here... I tested it this morning after getting 8 and 9.5 last night, I got a 10.

I think the other part is i need to run the pump faster longer...
 
I do not think it is how you are testing, it sounds exactly like circulation.. after you brush the pool and swim I bet the FC levels will be the same everywhere
 
cowboycasey said:
I do not think it is how you are testing, it sounds exactly like circulation.. after you brush the pool and swim I bet the FC levels will be the same everywhere
Click to expand...

Yeah... The learning curve :) I just assume things are crazy cause how everyone else says they run their pumps for 15 mins and check again... mine may need to run for an hour or so to do the same thing.

I basically have it run very slowly during the day to keep the water moving, and keep surface pollen at a minium, which I seem to get a lot of... and then at night for an hour it bumps up to 2 HP, and then shuts off over night, and at 530 am it kicks in to 2hp again for 2 hours before running at like 1/2 HP though the sunny days
 
There are only a few possibilities to consider here.
Testing error, dosing error or circulation
FC was higher after adding than you thought if you didn't test after
FC wasn't fully mixed in when you tested if you did test after
Your neighbor snuck over and added some bleach in the middle of the night
Pump on high and brushing can eliminate the mixing question
Using the 25 ml sample reduces the margin of error
 

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