taylor k-2006 & FC

[Guest]

I've got a Taylor K-2006 test kit which I began using this year, but have a question I'm hoping you experts can help with.

As per the instructions, I use 2 dippers of the r-0870 dpd powder and swirl until pink...alll fine. Next add the 871 titrating reagent until sample turns clear. Now here is my question my sample turns clear, but if the sample sits for 30 seconds to a minute the pink color returns. Is this normal or do I add the titrating agent until the sample stops reverting back to pink.

I'm asking because I'm having a hell of a time getting my CC down and FC up. I've added gallons of bleach, liquid shock and powder shock. I opened my pool 2 days ago and it is still cloudy.

Just today, I added 4 lbs powder shock and a gallon of liquid. I checked and my FC is still .5-1.5.

Ph is 7.2, ta is high @ 250.
CC has done nothing but rise over the last few days from 7 to 15.

I did just clean a ton of worms out today which should help some, not sure what else is in the pool as I can't see the bottom.

Any help would be appreciated. I'm really curious about the test kit though.

Thanks.

[me_too]

I've got a Taylor K-2006 test kit which I began using this year, but have a question I'm hoping you experts can help with.

As per the instructions, I use 2 dippers of the r-0870 dpd powder and swirl until pink...alll fine. Next add the 871 titrating reagent until sample turns clear. Now here is my question my sample turns clear, but if the sample sits for 30 seconds to a minute the pink color returns. Is this normal or do I add the titrating agent until the sample stops reverting back to pink.

I'm asking because I'm having a hell of a time getting my CC down and FC up. I've added gallons of bleach, liquid shock and powder shock. I opened my pool 2 days ago and it is still cloudy.

Just today, I added 4 lbs powder shock and a gallon of liquid. I checked and my FC is still .5-1.5.

Ph is 7.2, ta is high @ 250.
CC has done nothing but rise over the last few days from 7 to 15.

I did just clean a ton of worms out today which should help some, not sure what else is in the pool as I can't see the bottom.

Any help would be appreciated. I'm really curious about the test kit though.

Thanks.

Not sure about the chemistry behind the DPD-FAS but yes my samples do the same thing after they sit around a bit.

You add your two scoops of powder in your 25 ml sample , then add your 0871 drops until the water goes clear, that's the endpoint of the titration. Record this as free chlorine. (1 drop = 0.2 ppm free chlorine)

You then add your 5 drops of R0003 and if pink appears then titrate again with your R0871 until clear again. Record this as your combined chlorine (1 drop = 0.2 ppm cc)

Are you sure the cc reading is 15? This would require 150 ppm of chlorine to eliminate!

[murphyjp]

I have tested using both the 25ml and 10ml method and come up with the same results. FC 1.5 and CC 15.

When I opened the pool both FC and CC were 0. After the first shock my CC was up to 7. The more I shock the more my CC rises.

[me_too]

I have tested using both the 25ml and 10ml method and come up with the same results. FC 1.5 and CC 15.

When I opened the pool both FC and CC were 0. After the first shock my CC was up to 7. The more I shock the more my CC rises.

This is normal. At one point you'll reach a point in feeding chlorine that will destroy the CC, this is called "breakpoint" and is usually 10 times the CC level.

At 15 ppm you'll need 150 ppm chlorine and that *highly* unusual. For a 10,000 gallon pool you'll need 19 pounds of 65% cal-hypo.

Drain the pool completely. There is something in the pool you're not seeing.

[murphyjp]

I took a sample to the pools store to double check and the CC is as stated.

I can't drain my pool as it's an 18k gallon fiberglass in-ground.

I've got 12 gallons of 10% liquid shock I suppose I'll just shock the snot out of it.

Any other ideas?

[me_too]

Any other ideas?

Make sure you sweep the floor and remove averything from the bottom before you attempt to shock again.

[murphyjp]

I shocked last night and retested after 2 hours and found that the FC hardly budged but the CC shot up to 30. Am I maybe bleaching out the test results? If the chlorine level was too high could it interfere with both the FC and CC tests? I was also expecting my Ph to shoot up considering the amount of shock but oddly it remained low. The water does have the chlorine odor which reinforces the presence of CC.

My water is foggy blue and I've vacuumed blindly twice as I can't see the bottom. I've added some ph increase to get that back up and also put a dose of algecide in. I've got some clarifier I'll put in later too.

I'm inclined to let the pool filter for a few days and see what happens as I don't know what the heck is going on.

This is very odd for my experience with this pool. Last year was our first year and we opened to a green pool and simply added algecide a dose of shock and everything cleared within a few 2 days.

[me_too]

I shocked last night and retested after 2 hours and found that the FC hardly budged but the CC shot up to 30. Am I maybe bleaching out the test results? If the chlorine level was too high could it interfere with both the FC and CC tests? I was also expecting my Ph to shoot up considering the amount of shock but oddly it remained low. The water does have the chlorine odor which reinforces the presence of CC.

My water is foggy blue and I've vacuumed blindly twice as I can't see the bottom. I've added some ph increase to get that back up and also put a dose of algecide in. I've got some clarifier I'll put in later too.

I'm inclined to let the pool filter for a few days and see what happens as I don't know what the heck is going on.

This is very odd for my experience with this pool. Last year was our first year and we opened to a green pool and simply added algecide a dose of shock and everything cleared within a few 2 days.

I just thought of something. Are you using monopersulfate to shock the pool? Monopersulfate can interfere with FC/CC chlorine readings. Taylor has a deox reagent that you must add during the chlorine test to eliminate its interference.

The DPD-FAS bleaches out at 50 ppm so you're "fine".

I'd let the pH drop to where it wants to go, the lower the better, you get more desinfecting with a low pH. What's the history of the pool, how was it closed? Biguanide? Baquacil? What products were added last year? That 30 CC has got me thinking.

Regards,

[murphyjp]

Well after the big shock, I let the pool filter for a day and just monitored the water. The CC level went from 30ppm in the morning to 15ppm in the evening and then 9ppm the following morning.

At the 9ppm point I shocked again Thursday with turbo shock (cal hypo) at 11pm and checked the next morning and found the CC had raised again to about 12. After filtering for another day my CC dropped to 3ppm today.

I've just shocked again and will see what happens in the morning. I'm going to dump some liquid chlorine in late tonight to keep the FC up. I'll check in the morning.

I find the initial spike and gradual drop in the CC odd. I though if breakpoint was not reached then the overall level of CC would rise, which it initially does but then drops off. I'm still learning though.

To answer your questions, I had been using liquid shock, sodium hypochlorite, but am now using cal hypo powder.

The pool is an ingroud fiberglass, sand filter with zeobrite. This is our 2nd year with the pool and has been closed by our pool installer with shock and algecide. No maintenance chemicals are added in the off season due to snow loads. We opened the pool last year with no problem just added a few bags of shock and algecide and the pool cleared up within a day or two.

I've been baffled this year with the difficulty, but as I said I'm still learning. I'll report back with my latest results good or bad.