Join Date: Oct 2006
Location: Ranchi, Jharkhand, India
The Crown of Thorns - surface skimmer
Its quite a simple gadget. An upside down sponge filter drawing water from the surface. I used a 6 piece of pipe, 2" dia, for the body of the sponge filter (3 total of sponge and filter watte). The top is open and the bottom is a 2 socket fitted with a 1 adapter and small bit of 1 pipe fitted to the suction of a power head.
What actually special is the top intake. I have made vertical cuts, 1.5 long from the top, spray bar style, so that the water is drawn from the sides of top of the 2 pipe. I thought that 1.5 would be maximum difference in surface level of a tank. You have to set the surface skimmer so that its top is just higher than the highest level you would top up the tank.
Now if you have followed me till this point, you would say that the water will be drawn from the entire vertical 1.5 slits. No, it is not drawn from the entire slit but from the surface only. Inside the 2 pipe is a floating cylinder, vertically 1.75 which effective shuts off the slits. When you put the power head on; the water level in the 2 pipe falls and with it the floating cylinder, so only the surface water is drawn in. If the floating cylinder drops too much then the water flows in too fast and the height of the water in the 2 pipe rises; so does the floating cylinder cutting of the deeper water. So it is only the surface water which is drawn in.
I made the inner floating cylinder from the material of a soda pet-bottle. Used a band of epoxy putty at the bottom and a band of Styrofoam at the top.
The output of the power head can be directed at will, so if you want to avoid surface agitation, its simple to direct the output water away from the surface. Actually the entire design and execution was meant to find a way to deal with surface scum without agitating the surface.
I had not taken any pics while constructing as I was in doubt if it would function to my satisfaction. It was on all night and the surface this morning was crystal clear, quite a big surface 3'x 6'. Now I have a few pics of the gadget in place for you to view. The pet bottle you see in the background is my reactor device for DIY CO2.
If you have a choice, you have a problem, till you elect your choice. No choice, no problem, only consequences, learn to live with them.
Last edited by essabee; 11-27-2008 at 04:43 AM.