DIY projects

This prototype runs by a refrigerator timer motor and takes about 1 1/2 minutes for a complete revolution. I have noticed that rocks at low tide that are out of the water, but remain wet grow much more algae than rocks that stay submerged all the time. I am using that principal for this device to see if it grows more algae then my algae trough.
It is lit with 18 LEDs that are about 1/2" from the belt which is cotton cloth on a plastic screen which is simple to remove.
If it works ...

I built a few of these over the years and was not crazy about any of the designs but this one I made last month works 100%.
My reef now has a nitrate reading of 40 and I figured it would be a good time todesign a new Denitrification device but I had no idea it would work so good and so fast. They usually take a couple of months to fully work but I had it running for a month and I just tested it. Water going in has a nitrate reading of 40 and with just one pass through the device which takes ...

I kind of like bristleworms but now I just have too many of them. Whenever I move a rock I notice it is loaded with the little slimers. I recently had a small clam up on the rocks and it fell onto the gravel. The worms sucked it out in no time so now it is war. Over the years I have made dozens of bristleworm traps and just about any design works. You can even put a piece of clam or fish into a piece of stocking and they will be stuck all over it.
This design I made in about 5 minutes ...