Can You Power Wash A Gunite Pool? How Do To It

pool maintenance professional standing on deck next to pool with power washer

When you find yourself needing to give an old pool a deep cleaning, you may think it’s a lost cause. If you bought a house with an abandoned pool that’s green with algae, it can seem like an impossibility to bring it back to life.  You might be surprised however at how an old pool can look if you give it a good deep cleaning.   You may find yourself wondering can you power wash a gunite pool?

Can You Power Wash A Gunite Pool?

Yes, you can absolutely power wash a gunite pool. In fact, we have first-hand experience power washing gunite pools. However, this is not the only way to clean a dirty gunite pool. In this article we’ll explain how to power wash a gunite pool. We’ll share key takeaways from our experience and suggest an alternative that may work better.

service technician answering can you power wash a gunite pool by showing how to power wash an old blue gunite pool correctly

Lessons From Power Washing A Gunite Pool

The first time I power washed a swimming pool was at the request of a client.  We were putting a new pool in the following year but they wanted to freshen up the look of their existing gunite pool which needed some help.  I did a little research and assembled the tools I would need. I power washed the pool fully two times to make sure I was able to hit just about every spot on the interior.  

What I discovered was it doesn’t always look all that great when you power wash a pool.  The reason being there’s a streakiness to the way it cleans.  The water jet is powerful, and where there is a direct line of contact with the pool surface, there’s a clean area with a dirty area immediately adjacent.  It’s nearly impossible to eliminate all the streaks. However, one thing I would recommend is to avoid the temptation of getting close to the finish. Keep a good distance so your fan width is a few inches wide on the pressure washer.  Though I would recommend cleaning a gunite pool in a different way, power washing may sometimes be a good option.

How To Power Wash A Gunite Pool

If you’re planning on power washing, you’ll need to be sure you have a sump pump and a place to pump the water.  The favorite pump used by professionals is the Zoeller Cast Iron pump.  It’s a little pricey, but can take just about anything you throw at it and still work.  If this will be your only use of a sump pump, you may be able to rent one at your local hardware store and save a few dollars. 

Zoeller N53-1/3 HP Cast Iron Submersible Sump Pump (Non-Automatic) – N53
  • Zoeller 53-0002
  • N53 – 1/3 HP Cast Iron Submersible Sump Pump
  • Non-Automatic

The Zoeller pump however is a great investment if you see yourself needing to dewater regularly. You’ll need some additional fittings and flexible hose. However, without too much trouble you’ll be up and running in no time.  I’ve found it’s best to take the pump into the hardware store when buying the fittings you need.  It’s just easier that way.

If your pool is really dirty and you want to minimize any sediment from building up you can use a dewatering bag. Otherwise, check with your municipality about pumping to the storm drain. In most cases they will allow this, but always notify them of what you intend to do so you can get approval.  You don’t want to be discovered part way through the work and potentially have fines and stop work orders to deal with.

Alternatives To Power Washing A Gunite Pool

If you’d like an alternative to power washing a pool, it’s a good idea to consider acid washing the pool.  We don’t recommend homeowner’s attempt to acid wash their own pool.  Acid is nothing to mess around with.  The acid fumes can seriously damage the lungs, your eyes, and your skin.  Basically, when doing an acid wash you need to be dressed like you’re in World War 1, fully protected from the acid.  

before and after of alternative to can you power wash a pool in backyard with green algae in pool finish

The acid wash is an excellent way to burn off the top layer of crud and calcium build up on your pool.  In reality, you are trying to get down to a fresh surface of plaster.  If you have a pebble swimming pool, you’ll notice the color is more vibrant after the acid wash.  If you have a white plaster pool, you’ll notice the pool is now white again. It will no longer be yellowed from age.  Although, there is one ne negative to an acid wash. That is the finish will be slightly rougher than before, as the acid burns off the top layer of cement cream from the finish.  

Can You Power Wash A Gunite Pool Summary

So can you power wash a gunite pool?  Yes, you can power wash a gunite pool, but make sure this is the best option for you before you attempt it.  A few final words on this subject: Always be sure your pool can handle being drained without ‘floating’.  This is something all pool professionals should know.  If you hire anyone to do any work on your pool which requires draining the pool, make sure they are insured against the pool floating for full replacement value of your pool and the surrounding pool deck. Lastly, if you’ve tried power washing and an acid wash, you may need to perform a gunite pool resurfacing altogether.