Winter algae prevention

Mctwist937

Active member
Jun 5, 2016
37
Orange, CT
Hello

I live in New England water temps definitely get below where I’m told algae grows. In the spring each year my pool is always super green. I have been trying everything to prevent this but I can’t win. Closing late opening early. This year I added a slow release non chlorine shock float as part of a winterizing kit from Amazon, I opened the corner of the pool cover in late Feb to pump some water out and the pool was already green with freezing cold water.

Any additional tips or tricks? I have an In ground vinyl pool with a mesh safety cover. I have been using the TFP pool method, liquid chlorine, stenner pump, staging tank, for years and the summer seasons are a breeze so thanks for everything.

Thanks
 
Closing late opening early.
Which approximate dates ?

Are you closing per the temps, or the calander ?

Do you Overnight Chlorine Loss Test and raise the pool to SLAM FC at closing ?

With a mesh cover, I have to drain twice over the winter (maybe a third time depending on the year). I tie the pump high in a bucket to hopefully get mostly rain water up top.

20240113_134827.jpg

Then when I'm done I toss the hose onto the cover and drop the pump to the bottom and let it mix for an hour. I do about 20 mins each with the hose left, right and center.

Once mixing, you can add FC back to SLAM if need be (small stream / above the pump) and brush the floor well in that area. You can get a surprisingly large area with the brush with only a little window open up top.
 
  • Like
Reactions: Mdragger88
I usually close sometime in October I have waited until late October early nov and it’s still been green

You leave the pump in there all winter? I didn’t know if that would be a problem so I just do it manually

I used to slam to close and it was still turning green so the last two years I tried out those winterization kits which have granulated shock bags and a slow release float of the same
 
You leave the pump in there all winter?
No. I peel a corner back and dump the pump in only for the process.
I have waited until late October early nov
That should be plenty late for us. Are you diligent right up to the end of sesson, or do you slack ? (we ALL do, no finger pointing I swear :ROFLMAO: )

Either way, Overnight Chlorine Loss Test before close, then raise it to SLAM. I like polyquat for the early close people, but you're plenty late it's not needed.

Add more FC as needed when you drain, like now. Mix it well after draining, test/add, and mix it well again.

Keep an eye on the long range forcast and open right after the last overnight freeze.

I knew ZERO pre TFP. Maybe even less than zero. But my pool was obnoxiously front and center out our sliding glass door at the dinner table and I hated looking at the 'green trampoline' so I closed super late, and opened super early and never had a problem.

Now i do the same but have chemistry data to prove it will be fine.
 
  • Like
Reactions: Mdragger88
the last two years I tried out those winterization kits which have granulated shock bags and a slow release float of the same
If you’re using the “In the Swim” winterizing kit here’s what your putting in:

the granular bags are MPS - non chlorine shock
the winterizer is Copper Triethanolamine Complex - Algaecide
the winter floater is nothing more than Boric Acid
the winter stain away is a metal sequesterant
and the magic sponge somehow catches oil

So technically you’re adding no sanitizer to your pool during the winterization process just an oxidizer, an algecide, a PH buffer, and a sequesterant. You’re basically relying on any chlorine residual left in your water at the time of close to hold out all winter and destroy any potential algae.
 
  • Like
Reactions: Mdragger88
I have a solid cover & do slam level then an oclt & close her up. Water is 65 degrees or less & falling.
No polyquat.
Its clear as a bell upon my late march early April opening (before water gets above mid 60’s) and I generally still have target fc levels.
You’re running low on fc during the winter. Algae doesn’t die below 60 degrees it just slows down.
You will either need to add more fc throughout the closed period like @Newdude mentioned or add a solid cover on top of the cover you have to prevent dilution of your fc (you’ll need to keep it pumped off)
 
People love to blame the mesh cover for allowing ickies in, but solid safety covers billow in the wind just the same and let just as many leaves (etc) blow under.

I ran tests on my water last winter at different depths and it was more or less a sliding scale from 0s up top (rain through the mesh) to just how I left it at the bottom. Proving it changed my approach where I now try and drain higher up as shown above then mix well to redistribute what's left.

I used to just drain from the bottom, and lost all my salt, CYA and FC by pumping the dense water below with the good stuff in it. (CH would have greatly lowered also but I have vinyl so it's not an issue for me). But after draining them all every winter, not only was it spendy to put them back, but I left myself open to issues with little to no FC. My new approach helps both aspects.
 
  • Like
Reactions: Mdragger88
Thanks all.

I just partially opened to add some chlorine and stir and I was wondering (my pool is green) can I hook up my pump and put it on circulate as opposed to filter to help keep the pool mixed until I open? Or do I need to clean it up before turned the pump on? I’d like to keep it covered for a while cuz I have a big tree that just dumps all over it in the coming month or two I’ve determined it’s less work to remove the cover after letting the cover catch most of it.
 
Supposedly a cold snap is coming not quite to us, but close enough that it could go a little further than they thought.

I wouldn't fire up the equipment yet unless you are prepared to blow it out again if need be. Some nights below freezing aren't a problem. The artic blast that never came would be a problem if it decides to finally show up.

Whenever the time is, the pump can run with green water. The filter may clog quickly so use recirculate if it does.
 

Enjoying this content?

Support TFP with a donation.

Give Support
Get a solid cover and a cover pump. Before closing, bring chlorine level up to half SLAM. This way, nothing gets in during the winter months and water stays clear.
This was my suspicion upon opening this year.

I also have a permeable safety cover for my pool as a couple others have and it was swampy black-green upon opening. I inherited the pool and so I don't know what it was like opening with a standard tarp-like impermeable cover, but I'm thinking that using one of those might solve my opening woes by preventing all the wintertime rain dilutions and phosphate seeping in through the mesh. Any others can corroborate?
 
Others have mesh covers and report clear openings. It has to be the timing of closing(late) and openings(early) as well as Chlorine levels(half SLAM) prior to closing.

The phosphate issue should NOT be an issue because, even though phosphates are algae food, if Chlorine level is at the proper level, then you could have all the phosphates in the world in the pool, but algae cannot grow to eat it.
 
Phosphates are like putting a buffet out in the middle of the Sahara desert. Ain't nobody showing up to eat it. 'But you left food out !!!'. K. So what ?

When you properly chlorinate, you have no algae and it's food is irrelevant.

Also, exhibits A and B (old house/new house) that mesh covers aren't the problem. Timing and not enough FC are the problem. Human nature likes to blame things besides ourselves.

Screenshot_20240627_083828_Gallery.jpg

Screenshot_20240627_083901_Gallery.jpg
 
  • Like
Reactions: Mdragger88
I live in PA, and although I'm sure you get colder weather, I open to a crystal clear pool every year, and I have a mesh cover.

First, I follow the TFP recommendations for closing based on the temperature of the water, not a date on the calendar. Closing an In Ground Pool

Second, once the pool is no longer frozen, for me, that is mid to late February, I pop off all the corners of the cover and slowly add 2 gallons of 10% bleach. I pour about a cup to a pint in each corner walking around the pool to each corner. It might take me 30-40 minutes to add all the bleach. Then I recover. I repeat this step once a month until opening. There may be some debate about adding bleach to the pool without circulation, but I've been doing this for years without any staining. I think slow addition is the key to prevent slugs of bleach from staining the pool. In theory, the bleach should be warmer than the pool and that should also help with dilution.

About April, when the threat of freezing night time temperatures are over, I remove all my winterizing modifications from the pool and pump (remove gizmos, reinstall drain plugs, anything else, I can do without completely removing the winter cover). I then place the pump and filter in service for the April bleach addition. I run the pump for an hour or two when I add bleach in April & May.

When the water temperature is about 60 degrees, I complete my pool opening, and place the pump in full service (SWG is not placed in service at this time). I usually have some debris (leaves, worms and bugs) on the bottom, but the water is crystal clear. I put my robot in to take care of the debris. Once the robot is done, I test my chemical levels, add bleach to bring the pool up to SLAM level and hold for at least a day. I perform an overnight chlorine loss test, and if that is good (always passed), I allow the chlorine level to come down to normal, and begin adjusting water balance. I usually need to use bleach for chlorine additions for a week or two, until the water temperature will allow me to place the SWG in service.

I do try to delay the winter cover as long as possible, the grackles in our area are relentless. I opened in late April on year, and I had to run the cleaner almost daily, at the peak of grackle season, I was getting 100-200 droppings a day in the pool. The later I open the fewer droppings, but opening too late risks algae.

I'm not saying this is the right procedure for everyone, but this is what I do, and I have not had any issues with bleaching of the liner, or pump/piping ruptures.
 
  • Like
Reactions: Mdragger88
Thread Status
Hello , This thread has been inactive for over 60 days. New postings here are unlikely to be seen or responded to by other members. For better visibility, consider Starting A New Thread.