At last! - The Final Grow Bed Is Leak Free...

Just over five months from the day I started ripping the swimming pool liner from its depths, the fourth grow bed is holding water and ready for its place among the useful. After a 24 hour testing period in which the bed was filled partially with rock and then filled with water, the ground beneath the bed is still dry. No leaks in the new liner and the drain bulkhead is perfectly sealed.

Now it's time to clean the rock, which will be a few day process. The water from the cleaning process will be used to irrigate the garden and other yard areas. Since I don't want to flood the yard, I'll have to do it gradually. I simply hook up a hose to the auto-siphon drain and direct the water to different areas of the yard. This will be the first rock that I am going to thoroughly clean. I feel it necessary with the system running great and the water is looking good. I don't want to disrupt the cycle by introducing a week of cloudy water for the algae to feast on. With the first two grow beds I didn't clean the rock at all. It takes so much water to clean it, I couldn't justify wasting it at the time. With the third bed I partially cleaned it by filling the bed with water and draining it twice. I am going to do the same with this last bed, except I am going to fill and drain it about 20 times.

Grow bed without and then with the liner...


Some areas of concern with regards to leaks...

When constructing the bulkhead for the auto-siphon I had previously been putting the bulkhead on to the liner and then filling the bed with rock. The problem is once I started putting the rock in, the liner would adjust itself and the bulkhead would end up in a slightly different position. I would then have to try to stretch liner so the bulkhead and the drain hole would line up properly. Once filled with rock, the liner does not move. Stretching it was causing the bulkhead to leak. So this time, I partially filled it up with rock first, making sure all the corners and edges had plenty of weight. This would make sure the liner was fully in place and would not adjust later. I marked the position of the drain hole for the bulkhead. I then moved the rock out of the way and proceeded with the bulkhead construction. It worked like a charm.


Filling it up and testing for leakage...



Clean the rock by filling the bed with water, then draining it. Repeat many times...



It is time to locate some fish!