Green Pool for over a month

virginia · Postby **virginia** » Thu 07 May, 2009 10:34

Green Pool, also Nitrates =40:

FC: .4
TC: 6.2
pH: 6.5
TA: -30
CH: 250
CYA: 90

My pool: 18,000 gal., vinyl liner
Pool chemicals: everything the pool store sells

Lots of shock. Algaecide.
My pump & filter: Sand filter
Other info: I've shocked, brushed, vacuumed to waste, backwashed, etc etc a multitude of times. They have told me the only thing left to do is drain water. I don't want to do that, as we are on a well and water is precious to us. Live on a farm and YES we have recently fertilized surrounding fields.

I'm tired of fighting the pool and am ready to fill it with dirt. I have never used "chlorine bleach" but I read lots on your board here about it. Should I try this? If so how much? Help, please, thanks.

virginia · Postby **virginia** » Thu 07 May, 2009 10:42

I forgot to add that I HAVE chemically cleaned the sand filter. And when I say "pool has been green for over a month", it's probably been more like SIX months, as I just meant to say we pulled the cover off a month ago. I'm sure the algae has been hard at work all winter long.

Aquaclear-NZ · Postby **Aquaclear-NZ** » Mon 11 May, 2009 02:25

your water balance is all over the place
with the high level of CYA you have i would hazard a guess the "shock treatments" sold by your swimming pool shop are either Dichlor or trichlor based

With a CYA of 90ppm you need to get your chlorine level up to at least 14ppm
The big gap between FC and TC would indicate that you need to at least double this with your level of CYA

Draining some of the water - 40% and refilling with a fresh bacth will cut the required chlorine level by 50%
8 - 10L of liquid chlorine of around 13% solution or double of 6%

after this baking soda or alkalinity increase will need to be used to bring your alkalinity to the required level

Guest · Postby **Guest** » Mon 11 May, 2009 07:24

Thank you. But "ugh", draining water is the last thing I wanted to hear. I guess I'm going to have to BUY a load of water. Thanks, will let you know how this works out.

Aquaclear-NZ · Postby **Aquaclear-NZ** » Tue 12 May, 2009 15:05

the option is draining, or adding the larger amount of chlorine
Tis a pain, especially when you are obviously not on a town supply

good luck

Postby **chem geek** » Wed 13 May, 2009 01:09

There are other options for killing or preventing algae growth in spite of high CYA levels, but they have side effects. You could use a phosphate remover, but with your pool having fertilized soil blown in the phosphate level is probably very high so the phosphate remover will produce a LOT of precipitate that needs to be removed. This is also expensive in larger quantities.

Another option is to use copper ions as in copper-based algaecides, but you have to be careful since too much or a higher pH can result in metal staining, especially in plaster pools (though vinyl can still be stained).

Not great options which is why it is better to prevent the CYA from getting too high in the first place through judicious use of unstabilized chlorine after the CYA gets to a decent level.

virginia · Postby **virginia** » Wed 13 May, 2009 12:36

Drained bunch of water on Monday night, bought 3500 gallons, delivered to pool yesterday (Tuesday). Water is STILL GREEN this morning. I have vacuumed and brushed A LOT, from what I can tell there's nothing on either the walls or in the bottom.

Today's pool store testing:
FC: .3
TC: 4.1
pH: 6.5
TA: -80
CH: 240
CYA: 240 (this was 90 the other day? what the????)

Now they're telling me it's IRON, and to treat with their MetalFree product. And to put me on a weekly PhosFree schedule.

I've HAD IT UP TO HERE, am getting a SWG installed in a couple of days and switching to another pool supply store.

Postby **chem geek** » Thu 14 May, 2009 03:11

If the water were more of a clear green, then that could be copper, but with your low pH I find that unlikely. Iron oxide is usually rust colored, but iron carbonate can be greenish. Is your water mostly clear, but with a green tint or is it cloudy green looking more like algae?

If you've got metals in your water, then an SWG isn't going to help with that. The SWG is great once the water is cleared up and will maintain the water well if you keep the FC at least at 4.5% of the CYA level, but it's not going to clear a pool that's got a problem.

If you have algae, then read Defeating Algae and note that it is a sustained high FC reading that gets rid of it -- every time you've tested it there doesn't seem to be any significant FC reading. You can't get rid of algae that way. You also should have your own good test kit, either the Taylor K-2006 you can get at a good online price here or the TF100 kit from tftestkits.net here with the latter kit having 36% more volume of reagents so is less expensive per test.

virginia · Postby **virginia** » Thu 14 May, 2009 07:40

Used their MetalFree product. Water is still green this morning. BUT, also (per advice from "new" pool store) added 24# alkalinity increaser and 2 bags of "super shock". I'd say green is lighter but water is still very cloudy.

I realize I should purchase one of the kits you've mentioned. I actually have one but I'm pretty sure all of the reagents are out of date and I just never was comfortable doing the tests myself.

Soooo, about that copper. What if that IS what it IS? and the MetalFree didn't change it? what then? How do I know if it's copper the pool store didn't mention that in their tests.

virginia · Postby **virginia** » Thu 14 May, 2009 09:06

It just dawned on me that about a month ago I dumped 2 "jugs" of Sam's Club algaecide into the pool (when first uncovered it was nearly black with algae). After reading a bunch it seems that I may have overdosed the pool with algaecide (I don't know if Sam's Club algaecide has copper in it or not).

Could THIS be my problem?? :oops:

virginia · Postby **virginia** » Thu 14 May, 2009 09:15

I just found out, the 2 "jugs" were 2 gallons of Pool Brand Algaecide 40.

Postby **chem geek** » Thu 14 May, 2009 12:14

That looks like a "linear quat" which is a standard inexpensive algaecide that can cause foaming (as opposed to PolyQuat which is more expensive and does not foam). It does not appear to have any copper in it. If you still have the boxes, you can read the ingredients. I believe it will just say "Alkyl (60%C14, 25%C12, 15%C16) dimethylbenzyl ammonium chloride" and you won't see any "copper ..." in it.

If there are metals in the water, then a metal sequestrant could help. Lowering the pH some should have it get a little more clear -- if that happens, then it's likely the color is from metals though I don't know (from your descriptions) where they came from.

boppoolservices · Postby **boppoolservices** » Sat 16 May, 2009 17:45

hi,you have to start off with new filter media, otherwise the green will just go round and round,if it is clogged up,also check your spider gasket is still glued down.phil

virginia · Postby **virginia** » Tue 19 May, 2009 11:15

Finally blue, still a bit cloudy but can see the 3rd step now. NEW pool company installed SWG yesterday. They also looked at the sand in the filter and said it looked "Like New", so did not replace. Said it's just to take a little more time to get rid of the dead algae. Also, pump pressure is perfect.

Thanks everyone for their help! And I'm ordering my OWN test kit TODAY =)

virginia · Postby **virginia** » Tue 19 May, 2009 15:32

I do have a quick question: WHY would one pool store show the CYA to be 90 one day, then 200 a few days later. Yet pool store #2 shows CYA to be at 50 (3 different days/tests)

Not sure which to believe, and anxiously await my new test kit and I can see for myself.