There are occasions where the water level in your saltwater pool gets too high, possibly due to excessive rainfall or perhaps because your pool requires repairs.
The question is how much to lower the water level?
And are there consequences if you lower it too much?
The water level in your pool should be low enough that the water surface isn’t higher than the side skimmer but should not be too low that the surface is too low to enter the skimmer.
The graphic above shows a good example of a water line that is just high enough to easily enter the skimmer and is neither too high or low.
Let’s take a closer look at how to best manage your saltwater pool’s water level and why draining too much water or having a water level that is too high can both be problematic.
Reasons Why Your Pool Water Level Needs To Be Lowered
You may need to lower the water level in your saltwater pool for a variety of reasons. Here are some common situations when it may be necessary to do so:
- Heavy Rainfall: If your area experiences heavy rainfall or flooding, the water level in your pool may rise significantly. This can cause the pool to overflow, potentially damaging surrounding areas and equipment and flowing behind a vinyl liner if you have one. In such cases, lowering the water level can prevent damage and ensure the pool functions properly.
- High Total Dissolved Solids (TDS): TDS levels in a saltwater pool can increase over time due to the accumulation of minerals and other contaminants. If TDS levels get too high, it can affect the water chemistry and make it difficult to maintain the proper balance of chemicals. Lowering the water level and adding fresh water can help reduce TDS levels and maintain proper water chemistry.
- Equipment Maintenance: If you need to perform maintenance or repairs on your pool equipment, it may be necessary to lower the water level to access the affected area.
- Algae Growth: If you notice algae growth in your pool, it may be necessary to lower the water level and scrub the affected areas to remove the algae. Most time though algae can be treated with proper maintenance and algaecide.
- Renovations: If you plan to renovate or resurface your pool, you may need to lower the water level to prepare for the project. This is particularly true if you have to repair or replace a vinyl liner or perform maintenance on a concrete or gunite pool which would require the entire pool to be emptied.
- Winter Closing: If you live in an area that gets cold winters with snow and frigid temperatures, you will have to winterize your pool. This involves dropping the water level below the water returns, blowing all water out of the lines, capping them and removing pool equipment for safe storage inside. If you’re lucky, you might get enough snow over the winter to bring the water level back up again. Otherwise you’ll have to manually add water in the spring to open the pool.
Lowering The Water Level Too Much Has Consequences
Lowering the water level in a saltwater pool too much can lead to several issues related to the chemicals, salt levels, and water flow, which can affect the pool’s overall health and performance.
Water chemistry can be impacted
Firstly, when the water level is lowered, the concentration of pool chemicals can become unbalanced. For example, if the water level drops too much, the chlorine level concentration s can increase, leading to over-chlorination, which can cause skin and eye irritation.
In fact, every time you remove large amounts of water from your pool you are removing chemicals and run the risk of putting water chemistry out of whack. This could mean having to replace certain chemicals which in turn can throw other levels out of line!
Lowers salt concentration
Secondly, lowering the water level will decrease the salt concentration in the pool. When you pump out large amounts of water, you’re removing salt.
Saltwater pools use a salt cell to generate chlorine, and if the salt concentration drops below a certain level, the cell will not be able to produce enough chlorine to keep the pool clean. This can lead to algae growth and cloudy water.
Water flow problems
Finally, lowering the water level too much can cause water flow problems in the side skimmer. The skimmer is designed to remove debris from the surface of the pool, and if the water level drops too much, the skimmer can stop functioning properly. This can lead to a build-up of debris in the pool and an increased risk of clogging the pool’s filter.
If the water level drops below the skimmer intake, the pool pump may suck air instead of water, leading to inadequate filtration and a build-up of contaminants in the pool. The skimmer door can also remain open or closed which also causes the system to suck air.
If water flow gets too low, your chlorinator will (should) shut down to protect the salt cell which stops chlorine production.
How To Lower The Water Level In Your Saltwater Pool
The most common methods to manually remove water from your pool are:
Pool Pump Multiport Valve – If you have a sand filter or D.E. filter that requires backwashing, you can use the same method to drain water quickly from the pool.
Submersible Pump – Pool companies will often close a pool in autumn by using a pump that they place inside the pool and a hose run out to the road (if using your sewage system is allowed) to quickly remove water from the pool. You can do the same if you own such a pump.
Siphoning – This method involves using your pool hose. With the pool pump running, lay the hose on the ground with one end in the pool near a water return and run the other end of the hose to wherever you want the water to drain to. Go back to the pool and place that end of the hose in front of a water return to force water into the hose. Once the hose is full with water, it’ll create a siphon and as long as that end remains submerged, water will drain out.
It’s important to note that you should never lower the water level more than necessary. Doing so can damage your pool’s structure and equipment, and may also make it difficult to maintain proper water chemistry. If you’re not sure how much water to remove, consult with a professional pool technician.