CC - Wont go down!

[HarrisonHRG]

HI Folks,

Got an interesting one (and please id only appreciate any constructive feedback not the "This isnt the forum for that" bla bla - Please )

We have a persistent, High CC reading, of around 3-4PPM. I've done a SLAM for over 4 days with even double the PPM FC on the CYA/FC SLAM level. but still no change on the CC. - water is crystal clear.

We are using Sodium Hypochlorite @ 15% commercial.

Pool is 75m3, salt cell & VERY heavily bathed in, we have had at a rough calculation over 6000 persons in the pool within the last 9 months. (yes, i know that's a commercial pool level, but the TFP method has still been king over any commerical supplier!)

Test results:
PH; 7.4
CC: 3.6PPM
FC: 4.8PPM (just allowed to reduce post SLAM)
CYA: 15 (indoor pool, used as a moderator to protect the bather against HOCL as we can run up to 6-8PPM FC to maintain the supply)
TA: 165
SALT: 3000PPM.
TEMP: 30-31 Deg C.
CAH: 110

Ive seen alot of other posts online about MPS, would a non chlorine shock assist in us reducing our static CC levels? Any other suggestions?

what effect does MPS have on the bather?

Thanks folks appreciate your time in advance.

H

 

[JamesW]

A high use indoor commercial pool needs a system like UV to help manage CCs.

You also need a lot of daily dilution to replace the contaminated water.

Organic CCs are more persistent than inorganic CCs.

I recommend a properly sized Commercial UV system.

 

[PoolStored]

Clean your test vial with rubbing alcohol and retest FC and CC. Let us know results.
Use a 10mL sample and each drop is .5 FC/CC. Will save reagent.

 

[JoyfulNoise]

Not surprised at all you’re seeing persistent CC levels with that kind of bather load. @JamesW is correct, you are operating at commercial pool levels of use. The bather waste alone (sweat, urine, feces, etc) is going to create a constant load of organics that the hypochlorite will react with. Much of it will turn into persistent CCs rather than more volatile chloramines. In fact, if you are seeing high levels of chloramines on your chlorine testing then you likely have even higher levels of THM’s and DBP’s that your tests aren’t sensitive to.

You need a very large freshwater exchange and the installation of a commercial grade UV system, preferably with a contact/mixing tank. A mixing tank with Ozone would help too but there are a lot of expensive environmental controls that need to be in place to operate that safely.

MPS will only be a bandaid fix and the MPS itself will show up as CCs on your testing so it will be difficult to see if it’s having any effect or not.

 

[JamesW]

Pool is 75m3, salt cell & VERY heavily bathed in, we have had at a rough calculation over 6000 persons in the pool within the last 9 months.

6,000 people in a 20,000 gallon pool is very high use.

Can you explain the nature of the bather load?

Is this a hotel, gym or what?

How much "Chlorine" smell is there?

How much dilution do you get?

What is the water clarity?