I'm finishing up yet another winter of frustration caused by my Autopilot chlorinator.

I love this thing during the summer and have a sparkling clean pool without issues, but as soon as the weather starts to get cold and it decides to reduce the output my pool goes green. I run my pump equipment on the exact same schedule during the winter as I do during the summer. I only get a green pool during the winter. When this happens and I go look at the output for the chlorinator it has reduced to single digits or completely to zero due to temperature compensation (I assume).

Is there a way to set a floor below which the output will not be reduced or can I disable the "intellegence" of the system and tell it no to temperature compensate? I really hate manually dosing all winter just because my system decided it was smarter than the algae Another side affect of this is my CYA goes to zero every winter and I end up fighting that in the spring as well.

Anyone else have this issue or is it only me that has algae that loves the winter time. . .

thanks,
dave

Once the water temp drops to the low/mid 50's all salt cell slow/stop production. This isn't new. Most people switch to bleach. for a few months till the water heats back up.

If you are getting more rain than usual and drawing off the excess water, of course the CYA will decrease. So will the CH and you Alk and pH will change.

It sounds like you're not checking the water regularly enough.

Scott

The only way to "disable" the temperature compensation is to manually change the percentage to what you want it to be every couple of days.

I have been very happy with the temperature compensation feature, so far it has worked perfectly for me.

AutoPilot is one of the few brands that does not shut down at low temperatures. They do, however, limit the highest percentage you can set the unit to when the water is cold.

Do you have borates in your pool? I don't have a salt water pool, but I added borates nearly 2 years ago. I've been putting a couple of jugs of chlorine in the pool once a month or so since the weather turned cold and I haven't had any green water at all.

Before I converted from tabs to BBB I was constantly fighting green and black algae in the summer. Now my pool stays clear year round.

I have 50ppm borates.

I don't add, or remove any water during the winter. Some evaporates and some is added via rain, but the is no filter backwashing, spash out, etc.

My CH is always high (welcome to central TX), my Alk and PH are kept in balance with my acid injecting. The only water parameter that changes significantly is CL and CYA both go to zero.

My water temp does get close to 50 and actually got into the high 40's once this year, but it really doesn't get that cold here in central TX.

Sounds like I should just reduce the pump run time and manually dose as I don't really want to have to go out and change the % number constantly. I was hoping to be able to disable this "feature", but it appears its a no go.

thanks,
dave

This also describes my pool in Sacramento. The only difference I could detect is that I test for Free Chlorine thoughout the year (regardless of temperature) and will add liquid chlorine to supplement the SWG whenever FC begins to fall below target. In practice, this means when the water temperature drops to 50-51° F. and Free Chlorine drops below 2.5 ppm or thereabouts [my CYA ~50 ppm]. Another difference: I don't bother to change the cell output % during winter but the pump time is reduced by half.

This year that drop in temperature occurred in mid-November instead of at the end of December. It's risen in recent weeks back into the mid-50s but the SWG still needs a bit of help.

btw - You don't backwash the filter during the winter?

Dave, at 55 degrees or lower, the output will go to 1%. For some larger pools, this may not be enough to get a strong chlorine residual.
Not sure why you would have algae under cold water conditions though, but in order for you to get a higher chlorine residual, you have two choices:
Manual additional of chlorine
Press BOOST to energize the cell for 24 hrs of production.

I don't typically backwash the filter during the winter, just depends on if we get some major dirt or something.

Sean I hope you are not one of these people that believe the fallacy that algae doesn't grow in the winter. That has to be the biggest crock of poo poo that I have heard and still hear regularly. We live in South Louisiana and it gets in the 30's and 40's in the winter. Until I found this site I had always had algae problems whether it was 100 out or 40 out.

Yeah, someone at the PoolForum (I think it was Al) had some algae under ice over the winter. The colder water certainly slows down growth rates, but it doesn't prevent algae from growing completely. Keeping the proper amount of Free Chlorine (FC) in the pool relative to Cyanuric Acid (CYA) will prevent such growth. In colder water, the chlorine will last a lot longer -- I only have to add more every other week when my pool water temp is near 50F (my pool also has a mostly opaque safety cover).

Since CYA is dropping so low how about a floater, or more than one, using trichlor? My CYA fell to 20 this winter and we had > 1" ice during the big freeze. I haven't been too concerned by the drop as we have had very few sunny days all winter. Until last week my pool temps were in the 40s F. I'm adding CYA right now, in a stocking. It is taking forever for it to dissolve due to the cold water.

Be cautious purchasing HTH product or others. All of the "chlorine" products, newly stocked at my near by Walmart contain copper.

gg=alice

You might be able to get algea in the winter. You live where it doesnt get cold and stay cold for months on end. 30's and 40's aint cold Up north, no way algea can grow in the cold water up here. My pool freezes over by christmas and thaws in March. Sometimes days go by and it doesnt make 20 degrees. I open on Patriots/Marathon weekend (third week of April), to usually no FC and a crystal clear pool. IMO, anybody who has algea under ice had it when they closed the pool. Down south during the so-called winter, yea, maybe algea can grow. Where you have real winter, no way.

Algae grows fairly well in the antarctic ice pack. That said, it is very easy to prevent algae growth at low temperatures. The growth rate is so slow that it takes only tiny amounts of chlorine to keep algae in check at cold temperatures.

In practice, algae is extremely rare at temperatures below 50 degrees.

One of my neighbors gets algae every winter. Can't do anything for them, though; they're not interested in pood maintenance advice. (An expert, as everyone knows, is someone who lives more than 90 miles away and charges exorbitant fees.) It seems there are different opinions here about whether normal levels of chlorine should be maintained throught the winter (for pools that don't close, that is). I don't find it very burdensome to add a cup or two of bleach once a week, and the pool stays on the mark. Is there an argument to be made for allowing chlorine levels to drop so low that algae could take hold?

BTW -- An interesting article. I can't even imagine -35 degrees C. water!

Though I never expect to see -2°C at the bottom of my pool, a good many earth worms find their way there after periods of rain. They're not too intelligent: the worms abandon the waterlogged soil, crawl out to the safety of the pool deck only to commit suicide en masse, bellying up to the edge and throwing themselves into a watery grave. Cleaning out cadavers that made it all the way to the pump intake is a pleasant chore if you like clingy, squishy things.

This winter brought colder than normal air temperatures... in early December the dwindling rays of sun combined with arctic wind to drive the water temperature from 20 to 5 (C.) in less than two weeks. Last year there were two or three weeks when the water submerged below the magical half-century mark (F.) and I think I added liquid chlorine two or three times until the SWG came back to life. Now, mid-March -- more than 3 months since that threshold -- and I'm still adding chlorine. Water was 52 F yesterday. The "strong gradients of temperature" have not yet arrived.

My fav part of the worm cleanup is that wonderful bouquet when you pull the pump basket or skimmer basket out.

Scott

Fordsbyjay, no, I don't subscribe to the belief that algae doesn't grow in cold water conditions. It's very possible and I know it occurs. No need for me to repeat what the others have said about algae and cold water conditions.
Polyvue, I was just in Sacramento last week...it's was unusually cool there. Love the Sushi place at Arden Mall. Can the low chlorine contribute to algae growth? Absolutely. However, it's not like summer temps and you can drop down lower and not have algae growth. Keep in mind too that phosphates contribute quite significatly to the possibility of algae growth.

Perhaps the dissapearing CYA can be attributed to the absence of proper FC (for a period of time) allowing the CYA to be converted to ammonia....

Yup. Heard you were coming... put out the fire and turned off the heater just before you arrived. It's payback for the miserably frigid weather I experienced in Florida right before the new year. (I know, you probably don't even acknowledge Orlando!) Lots of good sushi places popping up in this area the last few years. Sorry about the weather. Come back in July - you won't be disappointed.

I see you have finessed that last sentence! Began testing for phosphates recently (because the test kit is cheap; this is akin to looking for your lost watch in a well-lit area) and having heard the many tales of high phosphate levels from board members was expecting a big number. I was to be disappointed: Just 250 ppb in the pool sample and a meager 100 ppb from the tap. That's not even enough to warrant a temporary guest membership in the Chem 101 forum! (I'm beginning to develop a strong dislike for negative ions.) Next week: tests for heavy water, barium and UFO sightings...