Does Hot Tub Water Kill Grass?

    If you’re new to the hot tub world, you may be worried about the safety of the water when the time comes to drain it.  After all, you want to drain it onto your lawn or use it to water the trees and such, to make proper use of the water and make sure that none goes to waste.  Right?  One of the questions that people tend to ask is whether or not draining hot tub water will kill your grass.

The short answer
    If done correctly, as directed, then your hot tub water will not kill your grass.  In fact, watering your grass, flowers and trees is a great use of your hot tub water!  However, doing it incorrectly could possibly kill your grass and anything else that you water, so you’ll really want to make teh time to read the instructions on that!  Here are the main things to focus on.

The chlorine level
    As you most likely know, chlorine is not good for grass.  It’s strong and grass is pretty sensitive to begin with.  Since draining your hot tub is not something you just randomly decide to do, plan it so that you add your last chlorine at least 48 hours before you plan on draining it, or even longer if you wish.  Before you drain the water, make sure the chlorine level measures at 0. 

The pH level of the water 
    As far as gras is concerned, pH is more of the issue.  In order for it to be safe water for your grass, you are going to have to make sure that it’s between 7.0-7.8 on your reading.  If it’s not within that range, you’ll be safer to use it on your trees or your shrubs, which are heartier with their ability to handle different water pH levels.  It will take a day or two before you realize that it’s caused a problem, so you can always test on a small portion of your grass if you want to be sure.

In the event of a splash
    If you’ve got kids or a few extra people in your hot tub, water will often splash over the edge and onto the pad below.  Of course, your hot tub should be on a properly sized and designed slab so that it doesn’t hit your garden.  However, if there are a few splashes here and there, your grass should be fine!  If someone is dumping bucketfuls out of the tub and directly onto the grass, you may have a problem.

    In most situations, the only time you’ll have to worry about hot tub water killing your grass is if you drain the water directly after adding your chlorine to your hot tub, or if your pH level is outside of the normal range.  Since these are both things that you can check before you drain your water, you’ll be a-okay to let it pour over your grass (though you will want to move the hose around to prevent flooding!

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