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Pool Startup Chemistry Question


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I just opened my pool on Sunday, and it was filed with algae, but I could see to the bottom. I shocked the pool with 7 gallons of 6% bleach, ran the pump for a couple of hours, let it settle, then vacuumed out on waste. Refilled water, threw some pucks tri chlor,in the skimmer, and ran filter for last couple of days, water is not green anymore but is cloudy. Tested my chemicals ang got the "locked up reading" tc-10, fc-0, cya-o, TA-120, ph-7.5. The pool store (Bioguard dealer) is recommending me to add 50# of dichlor to break the bubble. Can I just wait till the total chlorine evaporates, and then try a heave shock at that point? I don't really trust them.

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No such thing as a locked up reading. If you have no FC and it has all formed combined chlorine that means the chlorine has combined with organics or ammonia (from bacterial degradation of stabilizer) . Your CYA of 0 ppm is a dead giveaway unless you closed the pool with no CYA, which is highly unlikely. The only cure is to keep adding chlorine until you start holding FC. . How many gallons is your pool and is it plaster, fiberglass, or vinyl?

I would keep using bleach for right now get the FC levell up to about 15 ppm AND KEEP IT THERE (and keep the pool uncovered if you have a cover for it) until you start holding FC. TC is NOT important right now. it just means that all the chlorine you are adding is becoming combined chlorine. You can use dichlor to chlorinate AND get the CYA up a bit but I cannot tell you how much to sue because I don't know how many gallons your pool is.

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Waterbear,

Thank you for the reply, I have been taking your advice for a while now. My pool is 35,000 gallons, it is a vinyl lined pool with a sand filter. My original understand of the TC v FC was I needed 7x the amount of cl in ppm to get a reading. That would be 70 ppm. So I figured to let the sun burn all the cl out and try to restart the CL process. The pool is cloudy and have been vacuumed by me manually and the robot for the last couple times has been coming up clean. I appreciate your expertise and advise.

John

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To prevent the problem you'd have to maintain an FC level over the winter, but that is hard to do if you get freezing temperatures and disconnect your circulation equipment. At a minimum, you would close your pool as late as possible with the water temperature as cold as possible, preferably below 50ºF and you'd open up in spring as early as possible before the temperature got warm, again preferably at 50ºF or below.

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I live in Pa, so I usually close the pool in October, open up in May, i have a Merlin pool cover that lets the water through. I make sure all chems are balanced before closing, shock it with the suggested amount for winter, i add a gallon of algaecide 40 and close it up. I had a giant algae issue when I opened it on Sunday. I opened 4 other pools and 3 of them were as dark green as mine. Mine seems to be the only ony not responding to the initial shock treatment. I adjust frustrated the my neighbor' s pool I opened and closed with the same proces was perfect when I opened it. When the pool place told me I was crazy to use bleach and that stabilizer wasn't an acid, I realized that their suggestion of adding 50# of dichlor was one I was not going to follow. I was reading about soil bacteria eating the cya and I don't knows if at is possible in my situation(I don't have any run off into my pool it is elevated from the surrounding area.) could e large amount of algae initially cause the same problem? I have dealt with pools for 25 years and never had as many issues as I have in the past three years with this large of an inground pool.20x48. Thanks for your help.

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A standard Merlin mesh will let light in. Once the water is 60 or higher, algae grows.

Chlorine disappates.

Algaecide 60 is what you should be using, not 40 or 50.

Don't use dichlor. Use either 6% bleach or 12% chlorinating liquid. Powders have dissolving issues with colder waters.

Adding liquid chlorine and Algaecide 60, ever couple weeks, starting in the beginning of April, will generally reduce or eliminate the algae bloom untreated pools get with this cover and most other brands of mesh.

When the pool is opened, if it's green, shock it hard enough to kill the algae over night. Vacuum to waste the next day, once the algae has loosened it's grip on the walls and floor. Don't try to be perfect. Move fairly quickly as the water level, because you are in Waste mode, will drop quickly. Have the hose to the pool going too. You can pretty it up later in Filter mode.

Scott

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I Did all that pool.looks blue but cloudy and the resulting test report is what I am left with. I put some copper sulfate in the pool skimmer to kill whatever algae is in there. Now if I could get a free cl level without adding 40 gallons of bleach I would be happy. Any help on the cl would be appreciated. I did buy an ammoia test but I am not home yet to test it. I told my wife not to add anything until I get home. Hopefully with some advice from this forum on quantity of liquid shock.

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Does the algaecide 60 work better than copper sulfate crystals? I will definitely use that next year for closing. Should I add that now to make sue everything is dead before adding the cl or is the algaecide40 I added this opening, combined with three tablespoons of copper sulfate enought to kill what's left after the initial kill off with the 9 gallons of bleach?

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I Did all that pool.looks blue but cloudy and the resulting test report is what I am left with. I put some copper sulfate in the pool skimmer to kill whatever algae is in there. Now if I could get a free cl level without adding 40 gallons of bleach I would be happy. Any help on the cl would be appreciated. I did buy an ammoia test but I am not home yet to test it. I told my wife not to add anything until I get home. Hopefully with some advice from this forum on quantity of liquid shock.

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NOT a fan of copper (although it works). It stains pools and turns hair green and it STAYS in the pool either dissolved in the water or as stain on the surface (which can redissolve in the water only to redeposit as stain again under the right conditions!) With continued use can build up to very high levels in the pool. The algaecide 60 is polyquat 60 and it what I would recommend also. Look on the ingredients for poly [oxyethylene (dimethyliminio) ethylene (dimethyliminio) ethylene dichloride] as the primary ingredient in a concentration of 60% because some companies have been substituting cheaper linear quats that do not work as well in a 60% concentration in their "algaecide 60" products!

Another alternative is to maintain a 50 ppm borate concentration in your water year round since it is an algaestat. It is easy to do with borax and muriatic acid or if you want to support your Bioguard dealer I am sure they will be very happy to sell you Optimizer Plus (an expensive mix of borax and boric acid to make it pH neutral.)

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Since the CYA level is 0, the chlorine will dissipate fairly quickly. you shouldn't need more than 3 ppm overnight but during the day, that level needs to be maintained so someone will need to add bleach to maintain that level. The cloudiness is due to a lack of chlorine and a new algae bloom wants to get underway.

More chlorine that suggested at that CYA level is discouraged as much as adding any metal except grounded zinc for controlling electrolysis.

Scott

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Just added 5# of dichlor. Try to get 15 ppm level. My thought is that it would add some cya to the pool also and I had 50# already bought due to the advice of the Pool shop recommendation. I will try to keep it at FC of 15 as per waterbear recommendation and see what I get. Pool is cloudy still. But not green. Not improving either. Pump has been running 24 hours a day since Sunday.

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As I suspected. Basically you have to keep adding chlorine to oxidize the ammonia. It will convert into combined chlorine very fast and the FC will drop very fast so the TC reading will stay high. Ignore TC. it is the FC you are interested in. Keep adding it on a regular basis (at least twice a day if not more) to maintain the pool at shock level. Shock level is determined by your current CYA level and if you add dichlor that will continue to rise. You will eventually see the CC level dropping and the FC holding longer. Keep it up until the CC is 0 ppm and teh FC is holding...It can take a LOT of chlorine. If you have 30 ppm FC or higher I would only use an unstabilized chlorine source such as bleach since the higher the CYA the higher the FC needs to be to oxidize the ammonia since the CYA keeps chlorine 'in reserve' and not immediately available. AT 30 to 50 ppm CYA you will want to keep the FC at about 20 ppm or as close to that as possible. To determine dosing you can try the Pool Calculator.

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Well I shocked the $*** out of the pool starting yesterday morning. I used dichlorvos first couple of times to raise the cya and shock at the same time. I know I lost some ph along with that. As soon as the sun went down I started the 6 gallons of bleach per dose to get me to 10 ppm as suggested by the calculator, I got 4 shocks in last night until I went to bed at 2. Woke up this am and had a FC reading of 3/4. Soi shocked again. This time I adjusted to amount just to reach 10. I checked back 6 hours later during the day and still had some FC. shocked again. I tried to adjust the ph a little bit ago by adding borax to get the number up. I am planning to reshock at 10:00 then again tomorrow am. I leave for Boston tomorrow and I am trying to figure out how to have my wife add bleach while I am away. Maybe just one shock at the evening, and maybe cal-hypo tabs in skimmer during the day. Any suggestions. She won't do the tests. And I ran out of reagent for the FC I am using guess strips. Oh well fed ex needs to get me my new test kit by Thursday when I return.

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Without testing, could I have killed all algae/bacteria? The pool is cloudy but no chlorine odor. No ammonia levels were present this am or a reading of 0.25 ppm. Maybe time away with filter running can clear the fine dead algae. Any thought are welcome. Before reading this forums I added copper sulfate to kill algae and added algaecide 40 to prevent any new bloom to occur. I am hopeful that my filter just needs to do its job.

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While copper will kill algae, it can also create other bad issues that lead me to say simply, metals in pools are never a good thing to have.

Single quat algaecides are not your real friend. Algaecides generally help prevent algae but if algae can form, other. more dangerous bio-baddies can too. The best way to prevent algae is having the proper amount of residual sanitizer in the water already. In the vast majority of pools, that is chlorine. Kill the bio-baddy quick and it can't reproduce.

While algae may be the most visible, it isn't the most harmful. There are lots of different pathogens such as bacteria, viruses, parasites, and so on that algaecides do nothing for.

Chlorine also oxidizes or renders things like urea, sweat, and tanning lotions inert.

Scott

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Thanks Scott,

I talked to my wife and she said the pool looks a little better today. I really can't wait to get home and get this thing cleared up. Maybe it will be ok by the time I get home. One could only hope. I am not sure if I should have her shock it tonight without knowing the levels, or just up a gallon of bleach in and hope the filter takes care of the cloudiness. Any thoughts on just blindly shocking if I don't need it?

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