This is Poolside Chat where every week we answer your questions on how to fix and maintain your swimming pool. Poolside Chat is presented by INYOPools.com, helping pool owners find the right parts since 2001. In today’s episode of Poolside Chat, Rob and Matt tackle another common swimming pool question:

• How To Identify A Pool Stain

Now here’s your hosts – Matt and Rob.

I have a heated pool that had black algae 4 months ago but I got rid of it. Now suddenly there is stuff on the sides and bottom that I thought it might be metallic stains, but after treating it with stain remover it is still there. It is not slimy like algae and into the surface of the pool. Some patches are brownish, some purple-ish. Any suggestions what it is?

– Hannes

Well, your stain could be a stubborn black algae stain or it could be a metal stain like manganese; but you want to do is identify it before all else. If it’s an organic stain, you can take a chlorine tablet with a glove and rub it on the stain and if it lightens up then you know it’s organic. At that point, you can raise the chlorine level up high and add some algaecide like a black algaecide or a silver algaecide to get rid of the algae stain.

What if it’s not organic? What do you do then?

If it’s not organic then it’s a metal stain and in that case, I’d recommend going with a Jacks Magic Stain ID Kit which comes with three different chemicals to help you identify the stain. And we have all the chemicals and the Jacks ID Kit on our website so we’ve got everything you need to get rid of those metal stains.