Jump to content

Recommended Posts

I have read a lot of info on converting a pool back to chlorine, but would like some input on whether we are headed in the right direction. After using Baquacil successfully for 19 years (I have heard this might be some kind of a record), this year when we opened the pool we had nothing but problems and were told by the pool store we had to drain or convert. We have a 21x41 above ground oval pool with a deep end. Since we knew usually Baquacil users end up switching back we decided this was our time. When we started the conversion our levels were Baquacil Shock - 0, Baquacil sanitizer - 9. We got the pH and Alkalinity adjusted and shocked with a non-chlorine shock. We then began shocking nightly with a chlorine shock. That was 10 days ago. I have read that it takes a lot of shock or bleach and a lot of time. For the past three days the FC has held till morning (shocking in the evenings) at about 3 and the complete chlorine is .5-1 in the mornings, but by evening the FC is back down to 0. We have been keeping the pH and Alk adjusted and our hardness and other parameters are ok by our tests as well as the pool store. Are we on the right track, are we close, and is there anything we can do so we can get in the pool and wipe the drool off the faces of several kids? Any suggestions or advice would be greatly appreciated. (By the way the pool went through kind of a dark greenish blue color, but for the past week has been a pretty blue, just really cloudy, but I am told this is because we can't add the stabilizer/conditioner yet).

Link to post
Share on other sites

Keep hammering away at it with chlorine until it clears, you don't have more than 1 ppm FC loss overnight, and then change your filter medium since it will be loaded with baquagoo (a technical term) and then put in your stabilizer.

If you have a sand filter you will need to change the sand

If you have a cart filter you will need a new card

If you have a DE filter you will have to degrease the grids and then recharge it. If the filter pressure rises very fast then you will have to replace the grids because they are fouled.

When you add the stabilizer just pour it slowly into the skimmer with the pump running and run the pump continously for the next 24 to 48 hours. DO NOT CLEAN YOUR FILTER FOR A WEEK and don't test the CYA level for a week. It is very slow dissolving and will sit in the filter until it dissolves.

The color changes are normal as the biguinide is oxidized. Your conversion should go pretty fast because your biguinide levels were low when you started.

The cloudiness has nothing to do with lack of stabilizer as long as you keep hammering away with chlorine and keeping it a 10-12 ppm at all times as much as possible.. I would use liquid chlorine or laundry bleach, BTW.

Get yourself a Taylor K-2006 test kit


and do not depend on pool store testing. It is desgined to sell you chemicals so test yourself. Do not get the K-2005, you want a K-2006. You probably will not find it locally but it is readily available online in the US. If you are in Canada it is going to be more expensive but still worth the money and there are Canadian online retailers. In the US Amato Industries seems to have the best price and in Canada Piscines-Apollo is a reputable mail order retailer. There are others but I have done business with these two and feel they are reilable (and no, I do not get any kind of kick back or anything like that. I am just tyring to be helpful)

Link to post
Share on other sites

Thanks waterbear for the reply. I will get a better testing kit. Just a couple follow up questions. Since the Baquacil was low when we started, should it really be taking over a week and a half of daily shocking to get there? We shock at night and test the next morning, noon and night then shock again. Is it correct that we need to wait 24 hours to shock again even if the FC has dropped or can it be done more frequently? And just one more question - you recommended liquid chlorine or bleach, just wondering why?

Link to post
Share on other sites

Just get the FC up to shock level and KEEP IT THERE. You need a good test kit to monitor this and the K-2006 can test fc over 25 ppm with a precision of .2 ppm or .5 ppm and is NOT a color matching test. It is a titration with a distinct color change from red to colorless. It will also directly test combined chlorine and you want to make sure that the CC is 0 ppm to make sure you have finished the conversion. Here are videos that show the kit in action. Just click on the Pool/Spa link in the upper left then scroll down to see the videos for how the tests are performed. You do not need wait between shocking IF you are monitoring your chlorine levels and adding only enough to get you back to shock level. The reason I recommend soidium hypochlorite (liquid pool chlorine @12.5%, unscented plain laundry bleach @6%) is that it has the fewsest side effects of any form of chlorine. If liquid pool chlorine is sold in your area it is usually a better buy but if not then walmart bleach or any other house brand 6% laundry bleach is the same thing, you just need double the dose for the same FC level. Pool stores will tell you not to put bleach in your pool. Why? Because they do not sell bleach and lose money if you do. Sodium hypochlorite is an unstabilized chlorine source so it will not cause stabilizer to continue to rise as it is used . It will also not cause calcium hardness to continue to rise as it is being used.

For every 10 ppm of FC added trichlor will also add 6 ppm CYA (stabilizer).

For every 10 ppm of FC added dichlor will also add 9 ppm CYA

For every 10 ppm of FC added cal hypo will also add 7 ppm Calcium Harndess

Sodium hypochlorite adds only salt (actually all forms of chlorine add salt) and salt does not have a negative impact on water quality. In fact, many people add salt to their pools (when they do not have a salt water chlorine generator) because it brings the wate closer to the isoelectric point of the human body which meand less eye sting and less 'prune' fingers and toes.

The other option is lithuim hypochlorinte, also an unstabilized chlorine. This has nonegative effects but is extremely expensive to use.

Finally sodium hypochlorite (and the other unstabilized chlorine sources) are basically pH neutral on use. They are alkaine when added to the pool but the reaction that occurs when the chlorine is used up is net acidic so the overall effect on pool water is basicaly pH neutral. On the other hand , dichlor granules and trichlor tabs are acidic chemicals, particularly trichlor with a pH of around 2, and they still have the same acidic reaction when the chlorine is consumed so they have a negative impact on both pH and total alkalinity.

While we are on the subject, total alkalinity increase is plain baking soda. I do not care if the label says sodium hydrogen carbonate, sodium bicarbonate, or any of its other chemical names, it is still just baking soda and is much cheaper per pound at the grocery store!

Ditto for pH increaser (sodium carbonate, sal soda, soda ash, washing soda). You can find this in the Laundry aisle as Arm and Hammer Super Washing Soda for a lot less money. However, 20 Mule team Borax (also in the laundry aisle) is better for raising pH if needed because it does not cause such a big rise in TA compared to soda ash. Soda ash often causes the TA to go way too high when it is used to raise pH.

All forms of chlorine are usable if you monitor your water chemisty and male appropriate adjustments. Howver, if you live in an area that has an extended swim season, do not winterize, and/or have a cartridge filter or bump type DE filter then stabilized chlorne sources can cause more problems in the long run. The downside to unstabilzied chlorine is that it has to be dosed daily ( or you need an automatic way to add it such as a SWCG or a dosing pump). Trichlor tabs work wery well in erosion feeders on the other hand.

Link to post
Share on other sites
  • 1 year later...

There isn't exactly a "neutralizer" in the sense of some product that is specifically designed to breakdown biguanide. Instead, there are generally two chemical oxidizers that can be used for this purpose. The first and least expensive is chlorine. The process of conversion is colorful and takes longer, but works. The filter media will need to be replaced after conversion. That's the method waterbear described above.

The second chemical oxidizer that can be used to convert a biguanide pool is sodium percarbonate as described in the procedure in this link where the "OXYplus™" product (no longer available) is sodium percarbonate (added to water this produces hydrogen peroxide at higher pH) which you can get at The Chemistry Store for around $3 per pound. It's a more expensive approach, but goes about twice as fast. After step 5 in the approach, you want to finish off by using chlorine before you change the filter media.

Link to post
Share on other sites
  • 7 years later...

I have a 30,000 gal inground pool and last year decided to switch to chlorine.  The previous year we were constantly dealing with white mold and literally spending a fortune on the baquacil treatments, even CDX.  Last year we started out the year with a bacuacil level of around 20 and it never would drop below 10 all season.  We changed the sand in the filter then over the whole season we used 250lb of non-chlorine shock, 2 floaters full of chlorine tablets the whole season, 20 gal of liquid chlorine, 300lb of chlorine super shock.  The cyaunuric acid level was on the high side of where it should be, but still within the range.  The whole season we kept the alkalinity & ph perfect for chlorine.  After the initial rainbow colors when we started adding chlorine shock, it got better.  All season when we added chlorine shock in the evening we would still get mostly green clouds in the pool, but by morning the water would be crystal clear.  The water looked perfect all season.. best it had looked & smelled in years.  But... it would never hold chlorine and the baquacil never dropped below 10.  We were told is had something to do with the CDX "holding" the baquacil level.  Before we open this year we are draining the pool, cleaning it, changing the sand and starting with new water.  We spent a lot more on the chlorine side than it should have used, but still less than on baquacil.  My warning, if you have used CDX with your baquacil... just drain the pool first before converting it to chlorine and save yourself a LOT of grief and expense

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Create New...