Midway thru Baq -> Cl conversion before I knew the "rules"

[cbednara]

We decided to switch over from Baquacil to Chlorine this year when we opened (late May). The pool shop told us we needed to change the sand and they would handle the rest. The pool was foamy and yellow to start, then cloudy, then clear. We thought we were done, and started using the trichlor pucks and shocking once a week. The pool was clear, but always low on chlorine (1 or less unless we shocked). When the weather warmed up, we started to get a bit cloudy and started shocking more often. That was when I was told that we probably had algae ready to bloom and should start shocking at night to kill it off. Also I was told my CYA was high already and should stop using the pucks. I went several days, shocking to 15 -20 at night (temps were in the 95-105 so probably a wasted to try to keep it there). It would be down to half by morning and down to 0 by 10am. This is when I thought it could be the Baq. conversion. A sample sent to a local pools shop showed a Baq sanatiser level of 6, low but still there. I am on a full week of shocking it at night to 15 or higher. Been using a mix of 6% bleach ($2.50 for 182 oz), 10% from Rural King ($12 for 4 gallons) and Veratex ($17 for 4 gallons) from a pool shop in case the cheap Rural King stuff was low on Cl.

The pool is crystal clear, but not holding Cl levels. Any suggestions on how to proceed (temps are 95-over 100 every day, pool gets no shade). Any guess on how much more bleach I need to buy?

My guess on pool size is 17500 since it is a vinyl inground Grecian 17x31 3.5 ft deep on one end, 6 ft on the other Here are my latest readings used a ColorQ 7 drop meter (I hate sticks and don't trust myself to color match).

FC - 0.02
TC - 0.1
pH - 7.4
ALY - 202
CH - 248
CYA - 78

 

[JasonLion]

Re: Midway thru Baq -> Cl conversion before I knew the "rule

Welcome to TFP!

The high CYA level is going to make this take a while, as well as creating other complications down the road. It also means you should be raising the FC level to around 40 at least twice a day. With CYA that high, there is no point in restricting yourself to evenings.

 

[cbednara]

Re: Midway thru Baq -> Cl conversion before I knew the "rule

Welcome to TFP!

The high CYA level is going to make this take a while, as well as creating other complications down the road. It also means you should be raising the FC level to around 40 at least twice a day. With CYA that high, there is no point in restricting yourself to evenings.

Wow, that will be a challenge. Last night I put in 4 gallons of 10% and 3 182oz bottles of 6% and it only got the FC to about 20. I say "about 20" my current kit does not measure beyond 10 FC. I have ordered a Taylor K1515 kit to help measure high FC, but for now I am deluting my sample and multipling the results.

My guess is get it to 40 would take probably about 10 gallons of 10%.

 

[cbednara]

Re: Midway thru Baq -> Cl conversion before I knew the "rule

That is the other odd thing. No matter what type of Chlorine I use (6% bleach or 2 brands of 10%) the FC level does not go up as much as I think it should. I usually measure 30-60 minutes after pouring it in. I have tried pouring in the skimmer and walking around the pool as I pour it in. Same results. If I work backwards from the amount of FC rise to figure size of the pool it works out to be double my pool size.

 

[Bama Rambler]

Re: Midway thru Baq -> Cl conversion before I knew the "rule

The Baq is going to eat the FC very fast so it's not surprising that you're not measuring what you think it should be.

 

[cbednara]

Re: Midway thru Baq -> Cl conversion before I knew the "rule

The Baq is going to eat the FC very fast so it's not surprising that you're not measuring what you think it should be.

Does more bleach get rid of the Baq "better"? What if I just dump 10 gallons of 10% in at one time? Waste of money?

My pool is clear as can get, I am spending alot of money in Chlorine. At some point I would be better draining and filling back up (about $500 in water) or just living with low chlorine/high CYA and using pucks to keep a modest amount of FC and doing a high shock when it starts to cloud.

 

[Lershac]

Re: Midway thru Baq -> Cl conversion before I knew the "rule

I would drain half, refill and drain half again, the move on with the conversion but that's me. Or just go whole hawg and drain and refill, shock afterward to conversion standards, then change filter media.

 

[Leebo]

Re: Midway thru Baq -> Cl conversion before I knew the "rule

I think we'll all agree the pool stored nailed you with their poor info on this one.

If it were me I'd start by no longer using pucks. They're adding to your troubles. Second, I'd add 4 gallons of 10% and preform an OCLT. This will show you just how much chlorine Is being used up on baquacil overnight.

Last, Depending on the OCLT I'd drain 1/2 the water to lower the cya.

What test kit do you currently use? If its a drop based kit for the chlorine, I'd order more...you're gonna use ALOT on this swap. About how long is left in your normal swim season?

 

[linen]

Re: Midway thru Baq -> Cl conversion before I knew the "rule

Welcome to tfp, cbednara

I also vote for lowering the cya with a partial drain/refill before continuing on with the conversion.

 

[cbednara]

Re: Midway thru Baq -> Cl conversion before I knew the "rule

If it were me I'd start by no longer using pucks. They're adding to your troubles. Second, I'd add 4 gallons of 10% and preform an OCLT. This will show you just how much chlorine Is being used up on baquacil overnight.

I have stopped using pucks, I have been doing an OCLT for several days, though rarely getting up before dawn) and it typically drops to half of what I measured 30-60 min after adding Cl.

What test kit do you currently use? If its a drop based kit for the chlorine, I'd order more...you're gonna use ALOT on this swap. About how long is left in your normal swim season?

I am using a LaMotte colorQ I found at a reasonable (yet still high) price so I don't have to color match (uses drops and a photometer to give digital readout. I ordered a FAS DPD (Taylor K1515) to better measure high FC.