In part 2 of the 3-part blog on sand filters we got all the way through emptying the tank of the old sand and inspecting internal parts for damage. In this final blog of the series, we’ll work on re-filling and re-assembling the filter to get you back in operation. Although you will want to do things carefully, the good news is that the re-fill and reassembly of the filter will generally take less time than the first half of the project.

1. As we mentioned in the last blog you’ll want to be absolutely sure that you have purchased the correct amount of sand for the project and do not over or under fill the tank. Starting with a clean and empty tank, re-insert the filter stand pipe and install the laterals on the bottom. For some filters this means threading them in one by one inside the tank. For other models it may mean rotating the laterals 90° down into position.
2. Once this is done, position the stand pipe and laterals so that it is sitting in the middle of the tank and resting on the bottom of the tank. Positioning is the key, since you do NOT want to move the stand pipe up, down, or side to side after any amount of sand is added to the tank. Doing any of these things will likely result in damage to the stand pipe and lateral assembly, or prevent you from being able to re-assemble the multiport valve or top half of a split-tank type filter.
3. Once this assembly is sitting in place, you’ll want to do 2 steps BEFORE adding ANY SAND. First, either place an upside down Dixie cup or tape over the open stand pipe to prevent sand from getting inside of the pipe. IMPORTANT – Be sure to remove either the cup or tape before re-assembling the filter! Next, (with tank drain plug in place) fill the tank approximately ½-way with water before adding sand to the tank. The addition of the water lessens the impact of the sand on the laterals and prevents damage while filling the tank.
4. As you fill the tank with sand it is crucial to ensure that early on you are keeping the top/open end of the stand pipe centered in the opening of the tank. Moving the pipe (as stated above) after sand has been put into the tank will likely cause stress and damage to the pipe or laterals and create an opportunity for sand to begin entering the pool while the filter is operating. The last thing you want is to go all the way through this process only to find that you need to empty the tank, buy new parts and repeat the whole thing over again. Believe me, if this happens you won’t be a happy camper…or pool owner!!
5. Now, slowly re-fill the tank with the correct amount of sand – for most filters the sand level will come about 2/3 to 3/4 of the way up the tank. Too high and you may not be able to re-assemble. Too low and your filter won’t perform up to snuff. Remove the tape or cup from the stand pipe and attach the multiport or top half of the filter tank. Now is a great time to lube any o-rings and gaskets with silicone based lubricant for proper seal.
6. From here attach all connections in reverse order, open up any ball valves or plugs inhibiting flow of water and start the pump up with the multiport in “backwash” position – be sure that the pump starts pulling a prime within 30-45 seconds otherwise shut off and retry a few minutes later. Running a pump without water for long periods of time can and will eventually overheat and cause damage to components. Run the filter in backwash for about 1 to 1 ½ minutes to remove the fine particles from the sand bed, then shut down the pump and turn to “rinse” which can be run for about 30 seconds or so. Shut the pump off again and move the multiport handle to filter.

Inspect system for leaks and address immediately. That’s it! At this point if all is good, crack open a cold beverage of choice and give yourself a big pat on the back for a job well done. You’ve done well!

Thanks for reading and enjoy swimming…

Read Part 1 of the Blog Here: https://www.eztestpools.com/blog/sand-filters-101-how-important-is-sand-quality-part-1-of-3/

Read Part 2 of the Blog Here: https://www.eztestpools.com/blog/sand-filters-101-how-important-is-sand-quality-changing-your-filters-sand-part-2-of-3/