Salt Water Pool Is Light Green Color

by Annette Meares
(Myrtle Beach, SC)

I just changed my above ground pool into a salt system. It has a green tint to it. What am I doing wrong? I have had this pool for a couple of years and I have had not previous problems.


Do we add the same algae products to the salt system that we did with the old chloine system?




Thanks for the question Annette

If it's a solid green, it's probably algae. If the the pool water is a clear emerald green, it's more than likely a high metal contect.

You need to use a metal sequestrant. Since you increase the chlorine level, especially if you used calcium hypochlorite (granules) or a salt water generator, it may raise the pH level.

This will cause the copper to fall out of solution. Here are some very good metal sequestrants:

ProTeam's Metal Magic

Jack's Magic the Pink Stuff (regular)

Blue Stuff (fresh plaster)

Purple Stuff (for salt water pools) are some of the top sequestrants. You'll want to get a metal sequestrant that is based on HEDP, phosphonic acid, or phosphonic acid derivatives. In the long run, you might need to drain 1/3 - 1/2 of the pool water to get rid of the copper.

You may have caught it early enough to have it form into solids and backwashed out. Hopefully it won't stain your pool. Iron stains are one of the most difficult stains to remove.

If you're talking about algaecides when the question said "algae products", if you keep your chlorine between 1.5 - 3.5ppm, there shouldn't be any need for an algaecide.

Swimming Pool Chlorine

Pool Shock

Pool Chlorine

Chlorine Tablets

Pool Chlorine Tablets

But, if you want to use it, be sure to get a PolyQuat 60. This contains no metals and is safe for vinyl liners. Be sure to check out my pages on salt pool and salt chlorinators:

Salt Water Swimming Pools

Chlorine Generator

There lots of great information on the pool Q&A page for salt pools:

Swimming Pool Questions and Answers

Hope this helps and have a fun and safe swimming season. BTW...I had some of my best golf games at Myrtle Beach, not to mention a few Spring Breaks.

Robert

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Jan 18, 2015
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Slight Green Color To Water
by: Chris

I also had this problem with my pool. I used scale, metal & stain control last night and this morning it has almost completely clear. Thanks for that answer to this problem.

Aug 20, 2014
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HELP PLEASE! Light Green Color
by: Teresa

i have a 16x42 above ground metal frame salt water pool. i have drained, cleaned, vacuumed & refilled the pool 6 times & each time it will be clear for 1 day then start turning a light green tint in color & have little brown spots on the bottom of the pool.

i drained, cleaned, refilled pool & added salt monday. tuesday before i went to bed water was clear & no light green color. water readings were: total hardness 100, total chlorine 1, free chlorine 1, bromine 2, pH 7.2, total alkalinity 40, stabilizer 50 & salt 2630. wednesday mornin woke up to clear water but pool was light green color. water readings were: total hardness 100, total chlorine 1, free chlorine 1, bromine 2, pH 7.8, total alkalinity 120, stabilizer 50 & salt 2630. i was told to reduce pH, increase hardness, add algacide & salt. its been 8 hrs & now pool is no longer light green color its green.

water readings are: total hardness 100, total chlorine 1, free chlorine 0, bromine 0, pH 7.8, total alkalinity 40, stabilizer 50 & salt 3090. i dont know what else to do, i've been fighting this pool for over a month. HELP PLEASE!!!!!




Thanks for the question Teresa

First, if you're not using one, I'd suggest getting a good Taylor K-2006 pool test kit. I've made several videos on YouTube on how to use it.

I'll go with the last readings you have and what was told to you. Don't concern yourself with the hardness. This is mainly for plaster pools. The CH at 100ppm is fine.

Reduce the pH to 7.0 because you're preparing the pool to shock it. It's 20 oz. of muriatic acid to low the pH 0.2 per 10k gallons. Dilute the acid in a large bucket filled 2/3 with pool water and broadcast that around the perimeter of the pool, sweep very well, FILTER for 10 hours, retest and make another adjustment if needed. Chlorine works better at a slightly lower pH.

All the other readings are fine, including the TA, so don't worry about that right now.

It's time to shock the pool with liquid chlorine. It's 1 gallon to increase the FC 10ppm per 10k gallons. Adjust in the same manner as the acid for the pH.

Shocking is a process, not an event. The trick is to get AND keep the chlorine above 10 - 12ppm for a period of time. You'll need to manually dose the pool with chlorine to keep it at 10 - 12ppm. Make the adjustment at night, then retest in the morning. Be sure to have the pump running 24/7 and backwash once per day. You can go up to 15ppm, but no higher. Anything after that and you're wasting money and chemicals.

You'll know this is working because the pool will go from green to a white/grey cloudy and the chlorine will begin to hold better. First you may lose most, then 2/3, then 1/2, and so on. Once you only lose 1 - 2ppm of chlorine 8 - 10 hours after the last application you know the algae is dead. Now it's just a matter of filtering and backwashing once per day.

At the very end you can use a clarifier to help clear out any residual cloudiness. It's normally 5 oz. per 5k gallons for maintenance but go up to 10 oz per 5k gallons to help clear it out.

Be sure the chlorine cell is OFF during the shocking process.

This should clear up within a few days and should only cost around $20 - $30. It's a very easy fix. Once the algae is cleared up you can adjust the TA back to 80 - 100ppm using baking soda. It's 1 lb. to increase the TA 10ppm per 10k gallons.

Again, simply get the pH down to 7.0 or so and keep shocking the pool as per above. Sweep well to loosen up any algae. Yes, it should be that simple.

If you feel your situation is more complex than this, I do phone consultations for a donation of your choice. It makes things go much faster and many people have found it extremely beneficial, saving them time and money in the long run. All your questions will be answered. I have nothing to sell you so you know I'm not bias.

Pool Consultation

Hope this helps and have a great Summer.

Robert

Jul 13, 2012
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Light Green Salt Water Pool
by: radtech

I also have above ground pool for 2 yrs. now - changed to salt after 1st yr.

I have same issue..light green stains that feel like sandpaper spotted all over bottom. I got in with socks on & scrubbed, it worked some but still frustrated!!!!

Your question helped me alot & still searching.

Thank you!!

Radtech

Winter Park, FL

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