Frustrated in Ottawa


New member
Jul 26, 2010
I've been doing lots of research over the last week, along with multiple trips to the pool store, but I can't get rid of my algae.

Here's the pool history:

Had my 18' x 48" pool filled with a water truck about a week ago. Pool was used, bought a salt water chlorinator new to use with the pool. I accidently put a couple of bags of salt too many in the pool as it was filling, but only realized it after the guy left. So I had to dump some of the water and replace with well water. Bummer.

My chlorinator would tell me salt was good, then 1/2 an hour later it was too high, then it would be too low. Called the company and they said wait it out over a couple of days. I did, same result. Exchanged the chlorinator for another, the same thing was happening. By this point the pool was starting to get algae, as there was no chlorine production. I shocked it when I put the second chlorinator in so try and limit the damage, but it kept going.

At that point, I decided to go with a chlorine system. My 3-year old is dying to get in there so I thought this would be fastest.

2 days ago I put 250g of granular chlorine in the pool. No change.

Yesterday, I put 400g of chlorine in the pool. No change.

This morning I went for another water test, here are the results:

FC - 5.0 mg/L
TC - n/d
pH - 7.6
TA - 180 mg/L
CH - 220 mg/L
CYA - 30 mg/L

They tell me I needed 2.53 L of Muriatic Acid, I added 1.5L today and the balance will go in tomorrow morning. I also added 500mL of 40% algicide and another 500g of chlorine. Pool is still green!

Any thoughts or advice? I'd love for my son to go swimming!



Well-known member
Jun 27, 2010
Toms River, NJ
First, thank you for the updated test results. These go a long way towards helping you. I, personally, have one problem though. I cannot convert mg/L to PPM. That seems to be the standard for terminology here. Second, just a word to the wise. Pool store tests will suffice in a pinch but have been known to be very inaccurate at times. I would suggest you get a quality FAS/DPD test kit so you KNOW what your levels are. We can work off the pool store tests until you get one. That is as soon as I find a conversion for mg/L to PPM. :mrgreen:


Well-known member
Jun 27, 2010
Toms River, NJ
Go figure! It's a one to one conversion, almost. The decimals are so small I'll ignore them though. So, test results as follows:

FC 5ppm
PH 7.6
TA 180ppm
CH 220ppm
CYA 30ppm

No CC reading. I'm sure its above 1 though being that you are having an algae problem. Your FC is dead on for maintenance levels however you need to shock, and fast by the sounds of it. That means raising your FC to 15 (according to pool calculator) and holding it there until:
1. Your CC is less than 1.
2. Your pool is sparkly and clear.
3. You have an overnight chlorine loss of less than 1ppm.

Please use unstabilized chlorine (bleach or liquid chlorine) as you don't want to raise your CYA any higher than it is already.


Well-known member
Dec 3, 2009
Central Massachusetts
It's the same thing, for all intents and purposes here. mg/L=ppm.

A ppm is a mg/kg. But, a liter of water at 4 degrees C weighs 1 kilogram, so 1mg/L=1 ppm. give or take based on temp.

So his results are the same as what we use for ppm.

Edit: ok, you beat me to it.


LifeTime Supporter
Aug 20, 2009
North Central Texas
Does any of the sanitizer you are using have copper in it? How about the algaecides? Copper can give the water a green tint especially if TA and CH are not "balanced" for the combo with a normal to high pH. Did you truck in water because of the high metal content of your well water, maybe iron? Did you get initial reading on the trucked in water? What is it's source or what do you know about it?

Is the pool green cloudy or green clear?



New member
Jul 26, 2010
Well, it seems I've figured out the problem. Seems that my iron filter was not filtering as it should, and the green in my pool is a reaction between the salt and the iron.

My chlorine is so far off the chart it can't be measured, so algae is NOT the problem. That's the good news. The bad is that we could have been swimming this entire time, and now we (mostly my 3 year old) have to wait longer to get in the pool.

Thanks for all the advice.