how to remove rust stains from pool


Having a fiberglass pool has its many benefits. They’re generally just easier to own and manage in every aspect.

Fiberglass pools make for easy maintenance when compared to other types of pool, this is because of the fact that they rarely suffer from pool stains – when properly maintained and managed of course – making them much less a pain when it comes to keeping them looking appealing.

As well as easy maintenance, fiberglass pools tend to have other benefits over other pools too: they’re cheaper to run (this is also partly due to the low maintenance that they require because less money is spent on cleaning products and equipment) due to the low amount of electricity required to keep one going.

They need fewer chemicals than other types of pools, again resulting in the owner saving money. And finally, the smooth surfaces of fiberglass pools mean that swimmers are much less likely to cut themselves on rough or sharp edges.

But, and there is a but. They do have a downfall: Rust.

Despite their easiness to keep and maintain, rust tends to be terribly difficult to remove from this type of pool and it tends to form in fiberglass pools rather easily. Rust is the Achilles heel of the fiberglass pool – it’s ultimate weak point.

Do you own a fiberglass pool? Does your fiberglass pool have rust stains? Are you struggling to get rid of said stains? Yes? Well not anymore.

In this article, I am going to provide you with a step-by-step, incredibly easy to follow walkthrough on how to remove rust stains from your fiberglass pool.

I will be issuing you with tried and tested methods that I have put to use myself, in order to rid of the rust stains that had formed in my very own fiberglass pool. I did it. So you can too.

Come on; let’s get this show on the road! And this rust out the pool…You can also have a look at this video:

A List Of Useful Tools

Before we start the step-by-step guide on how to remove rust stains from fiberglass pools, I thought that I would provide you with a list of useful items that will certainly come in handy when you’re cleaning your pool.

I’m going to be sharing with you a couple of different techniques that you can try out to remove your stains, so there are items on the list that you may not need if you’re only trying one method.

So you mightn’t use all of them, but they can all no doubt come in handy in your pool cleaning endeavors. So, here it goes:

  • Soft-bristled brush – a fairly long one would be useful
  • Vitamin C tablets
  • Chlorine tablets
  • Ascorbic acid powder
  • A sock (bear with me on that one)
  • A pool pole
  • Rubber mallet

This is your armory. In it, you will find all of the tools that you need to get rid of rust. So come on, let’s put them to good use.

The Walkthrough

Seeing as there are different situations in which rust stains can occur, I will be teaching you how to go about solving the most two common types of rust stain: those which occur in shallow waters or the shallow end and those which occur in the deeper water, also known as the deep end.

As I bet you’ve already guessed, stains that occur in the shallow end are definitely a whole lot easier to deal with than those that occur in the deep end. But do not fret, I have the solution to both problems.

Now, before I begin with step one, let me make it clear that everyone’s stains will be different. There won’t be a single stain the same. My stain will be different to yours and yours to the next persons.

So, considering this, you have to make sure to remain positive if things don’t go your way instantly. Removing rust stains can often be quite tricky and it can take a little while and a few tries until they are totally removed.

But you must be persistent. These methods do work, but only if you do the work too. Now, without further ado, let’s begin the list.

Shallow End Stains

As a pool owner, these stains are your friend. They are both a lot less irritating and a lot less time consuming when it comes to removing them.

Unlike stains in the deep end, shallow end stains are much easier to access, which in turn makes them much easier to remove. And here’s how:

Vitamin C Tablets (Better For Smaller Stains)
  • Step 1 – Locate your stain and have your vitamin C tablets and soft-bristled brush at the ready. You may have to get into your swimming costume if the stain is too far away from the side of the pool or if it isn’t on the steps entering your pool etc. Basically, if the stain is somewhere that means you’re going to get wet, put your swimming costume on. Get near the stain, weapons in hand.
  • Step 2 – Take the vitamin C tablet and rub it onto the stain. This can become quite laborious, quite fast if your stain is of a larger description. But like I said, remain persistent and it will come off eventually. Alternatively, if your stain is actually rather large, you might want to consider waiting for the next technique, because the stain can be easier to cover with our next weapon choice.
  • Step 3 – Keep rubbing the vitamin C tablet onto the stain until the tablet is reduced to a powder. You can also try crushing up the tablets and then sprinkling them onto your stain but I find that rubbing it on works better as it actually begins removing some of the stain whilst you’re applying the vitamin C – due to the friction.
  • Step 4 – Take your brush and begin rubbing – quite vigorously – over the stain. Make sure that the vitamin C powder is still over the stain whilst you’re rubbing, without it, the brushing will be ineffective. Your stain should be considerably reduced.
  • Step 5 – Repeat the process over and over until your stain is gone.

Note: The same exact method can be carried out using chlorine tablets as opposed to vitamin C. The same results will be achieved.

Ascorbic Acid Powder (Better For The Larger Stains)

The same principle applies with this method. The only difference is that it is far more convenient when addressing the larger rust stains. Here’s how to do it.

  • Step 1 – Sprinkle your ascorbic acid powder onto your rust stain, making sure to cover the entirety of the stains area.
  • Steps 2 – Again, after leaving the powder to settle for a few seconds, vigorously scrub the stain, making sure to scrub the powder into and away from the stain. Leaving the powder to sit for too long will result in burning away too many layers of your fiberglass, you just want the acid to burn through the first layer as that is the layer that has been stained and burning through that layer will allow you to scrub it off.
  • Step 3 – Repeat the process until your stain has been successfully removed.

Deep End Stains

These types of stain can be a little trickier. Unless you want to get your scuba gear out and take a swim down to the bottom of the pool, the rubbing the vitamin C tablets on the stain technique is pretty useless here.

But, you can still use vitamin C to do the job; you just have to be smart about it. In fact, you can use any of the three that I’ve mentioned, either vitamin C tablets, chlorine tablets or ascorbic acid, they’ll all work just fine. And this is how:

  • Step 1 – Take whichever solution you want out of the three – it could be a mixture if you want – and put them into the sock (I told you to bear with me, it’ll all make sense now.) If you choose ascorbic acid powder, simply pour into the sock and tie a knot into it to keep the powder in. If you choose either of the tablets, put a handful into the sock, tie the knot and then crush them up with a rubber mallet.
  • Step 2 – Drop your sock into the pool, aiming for the stain. Use your pool pole to position the sock right over the stain and keep it pressed down for a minute or two. Begin rubbing the stain with the sock, making sure to hit all of the stain.
  • Step 3 – If you have an extendable brush, take out the sock and scrub the stain with your brush. If you don’t have a brush long enough, don’t panic. Just keep scrubbing the stain with the sock using your pool pole. It may take a little while longer in the deep end because you can’t generate the same power in your scrubbing, but don’t worry, it will come off.

And that is that folks, your pool is now completely rust-stain free! And all thanks to me… I mean, uh, all thanks to us…

Did you find this article helpful? Did you enjoy it even? Let me know in the comments section.

I wish you all the success in the world in your pool maintenance endeavors and I hope that these techniques work just as well for you as they did for me.

Now you can go on in confidence. Confidence that you’ll never be defeated by rust stains again! May you find this article on how to remove rust stains from fiberglass pools helpful.

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Staff Writer

SPP is committed to simplifying pool care with expert advice and valuable tips for stress-free pool maintenance and ownership.