Tired of opening to green pool-Do I have any options-Massachusetts


LifeTime Supporter
Apr 30, 2012
Massachusetts, USA
I live in Massachusetts and faithfully close my pool per TFP directions every year.
I need to winterize by blowing out pipes/antifreeze/drain pump etc. so I do not get freeze up in pipes. This means I cannot run my SWG year round and, due to pool water freeze-over, I cannot shock during winter.
Any tips as to how I can improve my algae situation in the spring with preventative measures?

Kindest Regards,


In The Industry
Jul 20, 2017
Windsor, Ontario. Canada
Lots of options on here. If your are opening to a green pool every year you are not closing correctly. No need to add anything over the winter. Just last week did my 41st year openings and not even a need for brushing nor vacuuming.


Mod Squad
TFP Expert
LifeTime Supporter
May 11, 2014
Franklin, NC
The key is to close late and open early. Cold water slows the growth of the green stuff.

Close later, even if it means the water is too cold for the SWCG and you have to chlorinate with liquid .

Open earlier, again even if it means the water is too cold for the SWCG and you have to chlorinate with liquid.

This may add weeks or months of addition pool care before it's closed and after it's open that you can't swim. But, this is easier pool care than a SLAM.


New member
May 8, 2018
Midland, MI
I live in Michigan and use Chlorine, but as long as you are keeping light out of the pool and opening sometime between early-mid May and June you really shouldn't be having problems. One thing we do is double cover the pool during winterization. I have a tarp that fits my pool size and we put on first that blocks the sunlight and then we install the Merlin safety cover over it. Because you are now blocking sunlight, and hopefully opening before temperatures get too warm it helps a boatload with minimizing algae growth.


Well-known member
Jun 30, 2019
New Jersey
I have a solid safety cover on my pool and when I opened it there was a few leaves and a bit of dirt, but the water was crystal clear.
What sort of winter cover do you use?

x Wild Bill x

Well-known member
May 5, 2016
Rochester, MA
I agree with close late open early. I closed our pool end of September, middle of October last year and am opening this weekend. I have already looked under the cover and the water is as clear as can be expected with a 99% mesh blocking safety cover. Plenty of worms on the floor and some leaves, but can easily see the deep end and no green algae. When closing I make sure to bring the pool up to shock level and add some Polyquat 60 for insurance. As mentioned we have a "99% solid mesh safety cover". I put that in quotes because looking through the cover I wouldn't say it block 99% of light, but it does block a bit.


Active member
May 8, 2014
Western Mass.
I live in MA and I’ve owned an an above ground pool for 5 years. I have always opened to pristine water, never needed to slam on opening.

1. About 2 weeks before closing, start letting the chlorine drift up. I have a SWG and running 3-4 hrs per day in late September when no one’s in the pool and the water is cool, allows the FC to easily go up 1-2 points per day.
2. 24-48 hrs before closing,dose the pool with enough liquid chlorine to get to SLAM level. For me, that’s 28.
3. Do an overnight chlorine loss test to make sure the water is healthy.
4. When pool water is consistently colder than 60 degF, BRUSH WELL one last time. Note that this isn’t the day the pool finally hits 60. Once you cover it, the cover will help retain heat. Add a lovely week of Indian summer, and you may be growing algae. Early October is usually when we fully close.
5. Open early - 2 weeks before Memorial Day is usually my target. But drop your thermometer in if you want to confirm the temp.
6. Do all your equipment maintenance before you pull the cover off. Nothing worse than watching pollen turn your blue water green because you need to spend 2 days getting parts and finding time to blow out your lines. Make sure to do a deep clean of your sand filter if you have one.
7. Pull your cover off and get it all hooked up and running. Test immediately and add liquid chlorine until it’s warm enough to run the SWG. I consistently have FC or 8-9 on opening -after a whole winter. And my cover is not well sealed - there are always a handful of ghostly pale leaves that snuck in under the tarp. Once I refill to proper depth, my pool reads FC 3. Every summer. Smells nice, looks amazing, and as soon as the temps top 70, the family jumps in.

Is any of that different from what you’re doing?

One year, the water heated up earlier than we expected. We pulled the cover off and for about a week, we dribbled chlorine around the perimeter and brushed it to distribute. Pollen tinged the water, but as soon as the filter went on, the blue came back. No algae - just pollen.
I live in Michigan and now open the first week of June every year with a mesh cover that makes my water turn green no matter what. A week before opening I put a pump attached to a garden hose in one end of the pool underwater on the stairs(I lift up the mesh cover on two same side corners), and put the end of the garden hose in the water on the other end of the pool. I then put a gallon of 12% chlorine in the pool about every other or third day and turn the pump on. The pump circulates the water from one end to the other and mixes the chlorine in the water. On opening day the water is way more clear, although there still is a lot of green stuff and worms that need to be taken out. Then I do the SLAM process which doesn't take very long at all to get things going for the summer.

I use to open it in April, it was still green, and no one swam in it because it was too cold. Now opening in June and using the pump method to circulate chlorine before opening makes things a lot easier with the SLAM, and I am not wasting six weeks of electricity for a pool that no one swims in when it is cold! Hope this helps.