Grit and sand sediment in the hot tub is mainly introduced by contaminates stuck to people’s feet. The cause can also be due to excess build-up of calcium in the water, and on rare occasions, the particles are introduced when filling up the hot tub.
The good news is that these particles are easy to remove and prevent in the first place. Prevention is always better than cure!! Further down in the article, I will give you top tips on how to avoid the problem in the first place!!
How to remove sand, grit and dirt from the bottom of a hot tub.
The best way to remove the particles is to suck them up physically!! Some people try to fan them towards the water filter, but this is a bad idea as it can overwhelm your filter. Also, when you remove the filter for cleaning these heavy particles may fall off the filter and enter the plumbing of the hot tub. Heavy particles that have entered the pipework can cause damage, but they also increase the surface area that bacteria can collect.
How to remove the hot tub sediment?
If you are happy to get into the hot tub, then just using a turkey baster will work. Place the nozzle next to the contaminants and suck them up! Once the particles are in the tube of the baster, empty them somewhere in the yard. Another tool I have found works well is the foam noodle water toys for children that suck up and shoot water. They are inexpensive and can be purchased in any Walmart for just a few dollars.
Are hot tub vacuums worth the money?
Most hot tub vacuums work along the same principle as the turkey baster, by sucking up the water at a high enough pressure that it pulls the solid particles into the tube. The advantage of using a hot tub vacuum is that it is long enough to use without getting in the hot tub, meaning that you will not disturb the sediment by getting into the tub!
The cost of the hot tub vacuum is also very reasonable, and I believe they are a good investment. They are great for removing sand and grit but work equally well at removing other contaminants such as grass which is floating mid-water and not being picked up by the skimmer and filter. I know I get a little obsessive about water quality, but I am sure we can all agree mid-water floating grass is annoying!!!! (just me then…)
I have seen electric, and battery powered hot tub vacuums which have their place if you are a professional hot tub cleaner, or if you manage commercial hot tubs. For those of us that have private hot tubs, an electric vacuum is not necessary. (But nice to have anyway!!)
How to stop sand and grit getting into the hot tub
Tip 1: Wear slippers or garden shoes to the tub
Wearing slippers while you cross the yard to get to the hot tub will stop your feet picking up contaminants that will be transferred to your hot tub. My family have cheap pairs of Crocs that they use when they are going to and from the hot tub. The advantage of Crocs over conventional slippers is they are made out of a foam material that does not absorb water as slippers do. They also have a reasonable grip on them, so my girls are less likely to slip over on the wet decking.
Tip 2: Use a foot bath to wash feet before you get in
Stepping in a bowl of water before stepping into the hot tub is hygienic and removes heavy particles like sand and grit. There are some shallow feet shaped bowls on the market, but a cheap alternative would be a large washing up bowl. The disadvantage of this method is that you will have to change the water frequently, which is not the end of the world, but it is another thing to remember to do.
Tip 3: Have an absorbent mat next to the hot tub to reduce sand and grit
The absorbent mat you choose must be good quality and have a latex backing so that it is non-slip. The mats I use are called Turtle Mats, but the closest I have found in the US are made by Beau Jardin.
These mats are a great invention, and I have them inside the house to reduce the mess our dog brings into our home. The mats are made from a highly absorbent material that traps dirt and sand. I have placed one of the mats at the bottom of the hot tub steps to catch some of the water that drips off my family when they exit the hot tub. The idea behind this was to make the ground less slippery, but what I found is that it reduced the amount of sand and grit that got into the hot tub!! Result!
They retail for about $20 for the smaller size, which I think is outstanding value. The disadvantage is they are indoor mats, so if you know rain is on the way, you’ll have to bring it inside. Also, now and again, you will need to hoover it or give it a good shake to remove the dirt. Despite this, I think they are a great way to reduce the standing water and ultimately keep the family safer.
Sediment caused by high levels of calcium in the water
Hard water contains high levels of dissolved calcium. When used in hot tubs can cause a few problems.
The first warning sign you may see is a white watermark on the hot tub at the level of the waterline. You may also notice that the seats feel slightly sandy or not as smooth as they were when you purchased the hot tub. As this calcium limescale gets dislodged, it sinks to the bottom of the tub and looks and feels very much like sand.
How to know if the sediment is sand/grit or limescale?
If you have none of the symptoms detailed above, then the sediment is most likely to be sand and not limescale. If you are unsure, the way to tell is to remove the sediment and dry it out on a serviette. When thoroughly dry, the sand will feel like.. well sand! Calcium will feel chalky and sharp when you rub it between your fingers.
How to remove calcium build-up in a hot tub?
If the build-up of calcium is light, it can be removed with a soft micro-fibre clothe. If this does not work, then you can increase the acidity of the hot tub’s water using the pH altering chemicals. Move your pH to between 5-6 for a few hours. This action will help dislodge the limescale, and you should be able to use your microfibre cloth to remove the calcium that remains. Some hot tub owners leave the pH low overnight to make the job easier.
Please remember not to use the hot tub when the water is acidic as it can irritate your skin. So, once you have removed the limescale, bring the pH back to a neutral seven before letting the family back in.
If you are unable to remove the limescale build-up, you will need to deep clean the hot tub when you next perform a water change. This process will involve using a hot tub surface cleaner to remove any stubborn scaling or marks. Do not be tempted to use general household products as they may permanently damage the surface of your hot tub.
What to do if your hot tub water has a high calcium content?
Once you have discovered your hot tub has high calcium levels, you will need to find a remedy. Otherwise, the scaling and grit at the bottom of the hot tub will come back. The high degree of calcium may be damaging other parts of your hot tub like the heater and pump, so to avoid expensive maintenance bills, you will need to add a product like Spa Scale Away. This product will ensure that calcium problems are kept under control.
Another product that I have used is SpaPure stain and scale preventer. Like scale away is softens the water, removing limescale and preventing new limescale from forming. If your water has a high dissolved metal content, this product also stops metal associated staining. If you know you’re your water has a high metals content then I would highly recommend you use a pre-filter to remove the majority of this.
How much scale product to add?
Adding chemicals to your hot tub water increases the amount of total dissolvable solids (TDS), and these reduce the effectiveness of your sanitizer. Given this, only add additional chemicals if they are needed and following the manufacturer’s guidelines regarding the dose.
If other chemicals like Spa Scale Away are required, then make sure you are changing the hot tub water at a minimum of three-month intervals. Unsure about hot tub maintenance? If so, I have written an article on hot tub maintenance that you may wish to read by clicking here!
Sand and grit can enter your hot tub when you carry out a water change
Sand grit and other contaminants can enter a hot tub via the hose when you are filling the hot tub up. One ingenious product on the market to solve this issue is the Pure Spa Pre-filter.
This filter attaches to the end of your hosepipe; cleaning the water before it reaches the hot tub. It removes 99% of contaminants and suspended solids, which is pretty impressive!! It also removes dissolved metals that can cause staining. All-in-all, this is a great product that I highly recommend.
If you use the product, you need to flush the filter for 30 seconds before you start to fill up the hot tub. This is to get the filter working to maximum efficiency, and any small particles of activated carbon in the filter will be dislodged.
Happy Hot Tubbing,
Brendan
