Fall is the perfect time for backyard and pool and spa renovations. Most everything is on sale this time of year and you can probably work out a great deal with pool renovators and servicers as their seasons are slowing down. If you’re looking for a pro in your area, check out our Pool Professional Locator. Pool Resurfacing and New Water Introduction Chemistry questions always arise when a pool is drained, or a new liner or surface is applied and refilled with water. Before draining a pool for any reason, please check with your local authority for any requirements on draining it. First and foremost, it is important to follow the instructions provided by the contractor installing the new liner or applying the new surface. It is also a good idea to have the fill water tested by your local pool pro. This will give you a head start on where your water is…balance wise, and what you may need to bring levels into proper range. With your new surface, your water chemistry will change. To get a better understanding of how much that is, compare new test results with ones taken before the water was drained. You may be surprised at the difference. Pros often like doing before and after tests to give pool owners an idea on what chemistry requirements they need to consider. Fill water can vary from water district to water district; some may have low calcium hardness, while other could be high. This can also be the case for other testing results. New plaster pool surfaces can affect the pool chemistry. Water with low calcium hardness (in general 150 ppm or lower), may leach calcium out of the plaster. Keeping calcium hardness levels between 200-400 ppm, will help prevent this from happening. Low pH – below 7.2, can also increase your chances of the pool water leaching calcium. In many cases, depending on startup methods used by your contractor, calcium will naturally leach until the plaster cures. Vinyl liners in most cases will not affect the pool chemistry at all. Just remember this simple rule of pool chemistry. Never add anything to the pool without a thorough testing of the pool water to determine what is needs. Enjoy your newly-renovated pool and happy swimming!