Green Pool Water tried everything Please Help

[VickiP]

I wish I found you guys last year!!! We replaced the sand today and WOW, the pump works so much better. We can actually see a bit of the bottom of the pool today still green but much better. It didnt hold the chlorine level overnight so we will just keep vacuuming, scrubbing and adding bleach everyday until it does. I will keep adding udates!! Thank you so much for the help!

[ChuckD]

Vicki, I'm also on a well and feel I need to throw this into the mix as something to keep in mind:

If you have added a combination of chlorine and significant amount of well water that has a high iron content, mix in some sunshine and you will get a green pool while you watch. I've reproduced this many times thinking I had an algae bloom. And it sure looked like one too.

I got suspicious when we were not yet fulltime residents in our home. We were in the process of relocating and we'd arrive once a month for a weekend. I had a small leak in the liner and when we'd arrive Friday night I knew I'd have to turn the hose on for a while to top it off, and then add a bunch of bleach, then off to bed.

Next morning I'd get up and pull the opaque cover off, and within 20 minutes the pool would go from crystal clear to deep green. Very, VERY frustrating. Especially when you only have the weekend to enjoy!

After reading something here I decided to instead fill the pool only via the skimmer so the water was first filtered through the DE and this was the solution. So also be aware that this combination, iron-rich well water, chlorine and sunlight will give you a false algae bloom. It ultimately filters out but no amount of chlorine will clear it.

Also, I read you have a sand filter. There are posts here, I think by Carl, about adding a small amount of DE to a sand filter to get all DE's benefits (and there are, once you've seen pool water filtered through it, it's beautiful). See if you can search on that, it's a small amount, like 1/4 - 1/2 cup but you should read those posts to get the right idea.

C.

[Watermom]

Very good advice from ChuckD who has been with us for awhile! (Thank you, Chuck!) This is what makes this forum work. People sharing their experiences with new people who are just learning the ins and outs of pool care.

Here is the thread he was talking about (adding DE to a sand filter).
http://www.poolforum.com/pf2/showthread.php?t=3742

[VickiP]

My pool is pretty clear with a tint of green. I did bleach again today but it is not holding overnight. It is gone in the morning. Why is that?? Do I just keep putting bleach in until it holds overnight and it is no longer green???

[VickiP]

Hi, Just saw Chucks post. What is DE??? I read the thread but not sure what it is. Also we did have the water tested and no iron but small amt of copper and after the metal out the copper was not even reading. Should we still use the DE?

[CarlD]

Short answer? Yes!

If your chlorine isn't holding with a CYA of 30 you are fighting something, almost certainly algae. You need to raise your FC level to 15 and keep it there, checking it at least 3x/day until it holds and your water is clear.

I opened my pool late this year due to the lousy weather and family issues that kept me going from NJ to upstate NY every weekend so when I finally pulled the cover off, for the first time ever I opened to a solid algae bloom. I poured in literally a full 5 gallon carboy of 12% LC figuring my 8 year old liner was already faded so Who Cares if it bleaches more. 24 hours later my pool was nearly clear, and 48 hours later it was clear. Because I didn't mess around and killed EVERYTHING possibly growing in the pool.

Now I don't recommend this procedure but I was (to my shame) impatient and a little annoyed and, with an ugly old liner (installers did a hideous job with the sand) I wasn't worried about bleaching it. I DID, however, add the LC to the return stream so it wouldn't settle anywhere.

My point is you are better off risking a little fading than tolerating algae. You gotta kill it and the best way is with bleach/liquid chlorine maintained at shock levels.

[ChuckD]

Hi Vicki,
DE is Diatomaceous Earth, of course! Everyone knows that. (just kidding).

You can look up a better definition of DE on Wikipedia than I can give, but suffice to say it does the same thing your sand does, but better because it's a finer filter.

http://en.wikipedia.org/wiki/Diatomaceous_Earth

It also requires a bit more work as you have to flush out the old and replace with new on occassion, sometimes frequently when you're fighting algae. But the results are the clearest water you'll ever see.

And because it's a naturally occuring substance it's fairly safe. When I flush, or more appropriately "backwash", I just run it out onto the yard. Been doing that for a couple years now and there's no trace of it or any damage. The first rain washes it into the ground.

But you can get the benefits of it with a sand filter too by adding a small amount. As you probably read, you'll have to add more each time you backwash the filter but the stuff's pretty cheap.

Hi, Just saw Chucks post. What is DE??? I read the thread but not sure what it is. Also we did have the water tested and no iron but small amt of copper and after the metal out the copper was not even reading. Should we still use the DE?

[VickiP]

Thanks so much Carl and Chuck. I will keep adding the bleach and keeping checking it. I will go to my pool store and get some of that DE and try it and see how it works. Thanks so much for the help I will let you guys know how it works.

[CarlD]

See if they have the 10lb box--the smallest amount. It will last years. Backwash then start with about 1/4 cup. Wait 20 min to 30 min and see if your pump pressure goes up 1 lb. If not, repeat with about 1/2 that amount. When the pressure has gone up 1lb, you'll know how much to use. If you put in too much, your pressure will shoot up and your flow to your skimmer and return will noticeably decrease. You'll have to backwash again to clear it out, then start again.

I don't think it adds anything during an algae fight--you don't need the filtering to be that fine until AFTER you've won the battle as the pressure will be rising every day from just the algae in the filter that you should be backwashing out everyday during the fight. After, the DE will help 'polish' your water till it looks crystal clear.

DE and skimmer socks are two of the cheapest, best additions to help keep your water beautiful.