After 5 years of endless fighting with algae during the summer, I finally decided to convert baquacil into chlorine. I just started conversion yesterday. After applying bleach and letting the pump recirculate for overnight, I can see that the water turns green now.

now I have a question: I am using a sand filter. I read from somewhere that during the conversion process if I don't use filter but just recirculate through the filter, I might not need to change the sand at the end of the conversion. And this is why I am only using 'recirculate'. I am wondering if using the filter would help the conversion. Any comments?

Welcome to TFP!

Yes, using the filter will help the conversion. And even if you don't use the filter, you almost certainly need to replace the sand anyway.

As chlorine combines with baqacil it quickly forms a goo the then continues to react with chlorine for quite some time. If you can filter that goo out and then backwash it out of the system (or remove it when the sand is replaced towards the end) you reduce the total amount of time and chlorine required to do the conversion.

If you have been using the filter with baquacil, there is already baquacil in the filter; which will gum up the sand at some point, even if you have the filter off right now. Leaving the sand in will dramatically slow down the final phase of the conversion and significantly reduce the filtering ability of the filter.

Hi, windy,

Welcome to the forum. Agreeing completely with Jason, baqua conversions are the one time when changing the sand is a virtual requirement.

YOu may never have to change it again but for this, it has to be done for the conversion to be effective.

We want the technicolor show!

Thanks, Jason & Dave.

Following you guys' suggestion, I have turned on the filter for a few hours. Added another 5 gallons liquid chlorine after sunset today.

Here are the pictures. Will add more with progress.

day 0: Before the conversion



day 1: First day after conversion (after 10 gallons liquid chlorine)

day 2: after 15 gallons liquid chlorine. Can see the bottom now under the strongest sunshine.

day 3: after 20 gallon liquid chlorine

morning:


evening:

day 4: after 22.5 gallon liquid chlorine

morning:



evening:

day 5: after 24 gallon liquid chlorine

morning:




evening: (DONE with conversion. got back the blue pool)

Before the conversion, baq reading was 14 and P.H. was 7.8.

So in summary, the conversion took:

1) 5 full days

2) 24 gallons (12% I guess?) liquid chlorine

3) twice of thorough vacuuming/scrubbing

4) a strong belief in the conversion

Windy - Your pictures are great, but test results tell the story too.
Is your FC holding at 15?
If it is, did you change out the sand and add CYA?
Is your CC .5 or less for two consecutive nights?
These three criteria, along with the pretty blue water, are the criteria for a completed Baq conversion...

Congratulations!

poolmom, thanks for the reminder about the completion criteria.

So my conversion is not officially done yet. I don't have the FAS-DPD testing kit that is recommended here. The local pool shop successfully sold me a bottle of cheap but entirely useless accuCheck testing strips (I didn't know this website yet at that time). So I am not sure about FC/CYA levels at this moment. I probably will buy Chlorine FAS-DPD test kit from a local Leslie's store over the weekend. Also, I am planning to change the sand too even though I just had it changed last year.

BTW, any one has good experience with the sun cover? some website boasts it can increase the water temperature by 10-15 degrees. Hardly can believe this claim, but if it does, it would help my family enjoy the pool much more.

If you use a solar cover consistently it should get you about 10 degrees.

Do you mean a solar cover blanket, or some other specific product?

Jason, thanks for confirming this. Now I am really inclined to get a solar cover.

My pool is rectangular (21x40) and the stair is outside the rectangular. Does it mean I have to buy a bigger one (say, 24x40) and then cut it to fit the actual pool? or can I just buy a small one (say, 20x40) and leave some surface uncovered?

yes, I meant a solar cover.

As long as the great majority of the surface is covered you will be fine. Having a good fit around the edges helps in windy areas, but isn't essential.

When trying to get the FAS-DPD test make sure it's actually FAS-DPD and not just DPD. You probably already knew this, I just wanted to reinforce it because a lot of Leslies don't carry the FAS-DPD in stock.

We love our solar cover. It's a 12 mil clear and has definitely warmed the pool a good bit. I can tell a big difference when I get lazy and leave it off for a night.