Why is my pool green after filling with fresh water?

PSC Ep. 89: Why is my pool green after filling with fresh water?

In today’s episode of Poolside Chat, Rob and Matt tackle another common swimming pool question: 
I just filled my pool and the water’s green. Why did this happen?

Most people are going to assume that it’s algae, but if it’s brand new water, that’s probably not the cause. It’s more likely that you have a lot of metals in the water, copper or iron. Your first instinct when you fill your pool with new water, is to shock it. But that shock then oxidizes the metals, that chemical reaction then causes the green hue in your water. This is common with refills that used well water or even water that hasn’t been shocked but instead contains a high level of metals.  

What can you do about it?

If you’ve already filled the pool and the water is turning colors, your first step should be to add a metal sequestrant like a Metal Control. Sequestrants do not purge the water of the metals but instead suspend it, prevent it from causing stains or unwanted effects. If you want to purge your water of metals, you’ll need a metal remover like CuLator. The CuLator metal remover is available in cartridges that can be inserted in your pump or skimmer basket

If you haven’t filled the water up yet, treat the water as you’re filling it with Metal Control. We’ve seen some cases too where people will shock it and they’ll add a metal– not a metal control, but an algaecide with a lot of copper. The copper in that algaecide can react with the shock and cause a green pool too so that could be a reason.

If you are planning to fill your pool with well water, a simple bobby hose extension can filter out metals as you fill the pool; this can elimnate or atleast reduce the need for further metal treatments.

If you have any other ways of filtering metals or suspending metals in your pool water, please leave a comment down below. For all your pool and spa needs, please visit us over at INYOPools.com

12 thoughts on “PSC Ep. 89: Why is my pool green after filling with fresh water?

  1. I filled out pool up with well water using a filter attached to end of hose. It was slightly cloudy. I valences the ph and shocked it. The shock turned it green….. What do I do know? Will Clorox scale, metal and stain control work as a metal sequestrant?
    How long will it take to clear up?

    1. Filled was well water took several days because of her will and it’s turned very green with algae what do I need to do

  2. What do we do if we have already added an algae ode to the pool? What do we do now to get rid of the green in a newly filled pool?

    1. I filled out pool up with well water using a filter attached to end of hose. It was slightly cloudy. I valences the ph and shocked it. The shock turned it green….. What do I do know? Will Clorox scale, metal and stain control work as a metal sequestrant?
      How long will it take to clear up?

Leave a Reply

Your email address will not be published. Required fields are marked *

Recommended Resources

what is the difference between suction, pressure and robotic pool cleaners?

Poolside Chat Episode #21: Suction, Pressure, and Robotic Pool Cleaners

This is Poolside Chat where every week we answer your questions on how to fix and maintain your swimming pool. Poolside...
Read Now
PSC Ep. 76: What to do if your multiport valve does not have a winter setting

PSC Ep. 76: What to do if your multiport valve does not have a winter setting

In today’s episode of Poolside Chat, Rob and Matt tackle another common swimming pool question:  If I don’t have a winter...
Read Now
Liquid Reagent vs Test Strips: Which is more accurate?

How to Test Pool Water: Liquid Reagent vs Test Strips – Which Is More Accurate?

November 13, 2024
In today’s episode of Poolside Chat, Rob and Matt tackle another common swimming pool question: Both methods are adequate options for...
Watch Now
Push-Pull vs Multi-PorFilter Valves

Poolside Chat Episode #27: Push-Pull vs Multi-Port Valves

This is Poolside Chat where every week we answer your questions on how to fix and maintain your swimming pool. Poolside...
Read Now

Looking for pool parts?

Shop Motors Shop Filters Shop Pumps Shop Salt Systems Shop Lights Shop Cleaners
Copyright © 2024 INYOpools All rights reserved