22 March Prefilter Work

A group gathered to work on the pre-filters. They removed the bag of sand and discovered the bag seam was still holding. They removed all the pebbles so they could add a small piece of scrap plastic. There was a concern the cap was being pushed down and air was not able to get under the cap to build pressure. The piece of plastic was a small section of a connector that was cut off.

Small piece of plastic used to keep the cap from touching the bottom of the filter

 They replaced the pebbles and put a piece of screening down. They tested to make sure the sand would not go through the screening. Instead of the bag, they put the sand in a bucket with just one hole. The Tantalus worked and the flow rate was better UNTIL all the air got sucked out and the top bucket become welded to the bottom bucket. A finesse of the design is needed.

Caleb suggested a completely new design. We will consider two teams on Sunday night:one for the new design and one for the current design.  We will send a sample of the main bio-filter water to Endyne on Monday for solids testing. This will help us know if we are dealing with actual contaminates or just sand flowing through the filter barriers.