Day 2 of BBB and I am using a lot of Chlorine...

[gatorbrit]

I converted to BBB a few days ago. Drained pool about 50%, and adjusted all chems. SLAMed the pool (using recommended procedure)

Today I started the day with (all tests done with TF100 kit)
at 7am
FC of 6.5 (added 179 oz bleach last night)
CC 0
CYA 35-40.
Ph 7.3
TA 110

It was a sunny day, no swimmers, temps mid 80s.

Now 5:30pm
FC 0.5 :grrrr:
CC 0
CYA 35-40
Ph 7.3
TA 110.

To get up to 8 ppm CL pool calc suggests 204 oz of 8.25% bleach which I added - about a jug and a half.

Pool is crystal clear - absolutely sparkling. So what gives? Adding 1.5 jugs of bleach a day is going to get expensive.

I just can't figure out what I am doing wrong.

 

[RobbieH]

When you performed the SLAM process, did you perform an OCLT as a part of determining if the process was complete?

 

[techguy]

Do you have a light in your pool? Ladder? If you have a light, I highly suggest you take the light out and see what you have behind it. Ladders are also where algae likes to hid.

 

[gatorbrit]

So -- this seems like to much chlorine demand correct?

If so then I will do the overnight test again to be sure. I don't have ladders, but I do have lights.

With the overnight test, should the pump run?

 

[Smykowski]

Yes and yes.

 

[gatorbrit]

Got it.

 

[techguy]

If you have lights and you fail you OCLT, pull out the lights and clean behind them. I have read of others fighting FC loss for 10 days to find a garden behind he lamps.

 

[gatorbrit]

Here are the results of the OCLT
Last night FC = 9.25
This am FC = 8.5
and CC =0

I think we passed the test.


My guess is that maybe I had some algae that has gotten eaten up over the past day or so by the Chlorine - and now it is gone. I think I will leave it today and see the loss again during the daylight hours. If I am still loosing a lot, then I will SLAM tonight just in case.

The other possibility must by my CYA which is in the 30-40 range. I might need to push that up a bit. But I will wait a day to do that.

Although this is a bit of a pain - now that I understand the process (thanks TFP) I now understand the interaction of the different factors that affect my water.

 

[BoDarville]

I now understand the interaction of the different factors that affect my water.

This is a big part of being a BBB'er and puts you in control of managing your pool water.

 

[JohnT]

It's also pretty easy to get fooled on the CYA test. If you can see any hint of the dot in the tube, you need to add more liquid. HIgh chlorine loss during the day but not overnight sounds like your CYA is on the low side.

 

[gatorbrit]

Update: I started today with 8ppm FC, ended up with 2ppm. Still a 6ppm loss. I think this is because of my CYA. It is gradually coming up, but I am reluctant to adjust too frequently because of the time it takes for the CYA to absorb (see my post http://www.troublefreepool.com/cya-absorption-rates-and-time-between-adjustments-t69244.html)

So I will check the OCLT again tonight and keep an eye on consumption tomorrow.

Still - even with this tweaking going on the pool is clearer than it has ever been (it was installed in the spring).

 

[Smykowski]

After you run the OCLT tonight, target an FC of 10 tomorrow morning. You don't want your FC dropping below 3 because then you're just asking for algae to gain a foothold. Even at 10 you're well below shock level for a CYA of 40.

 

[gatorbrit]

I am actually tempted to go ahead and SLAM again just to be sure.

 

[techguy]

If you did and OCLT you would KNOW if you needed to SLAM.

 

[gatorbrit]

You are right - I am just neurotic. I need to trust the science!

 

[techguy]

It takes some time to adjust from the "add something, wait, hope, pray" mentality of pool store methods.

If you test and it says to add A, add A, if not...

 

[gatorbrit]

Just an update. I still am only loosing less than 1 ppm overnight :-D

During the day I lost about 2ppm for FC (cloudy day) I went from 10 to 8. I will probably target 8ppm for tomorrow morning.

My CYA is 40.

All is well with the world. I think I have reached a stable and balanced pool - water is beautiful - Sparkling clean.

THANK YOU!!! Troublefreepool.com!!!!!!

 

[duraleigh]

Nice work!

 

[gatorbrit]

Nice work!

And it really didn't take too long. I started the process on Saturday with a partial drain.

 

[Butterfly]