update:
good news and bad news
i learned that a 2" screen on a 5,000+gph closed loop pump will suck in a sea hare and peanut worm, partly through the screen and kill them.
i have ordered a 4" screen in hopes that it will have much less "pull" due to a larger surface area.
i also woke up in the night thinking if i tried to pull the screen off the pvc and pulled up the pvc also that i would have a big problem with the closed loops and sand. so i put a kind of anchor through the bottom of the pvc and put rocks on it in the tank. that should hold it down once covered with sand.
<a href="http://s93.photobucket.com/albums/l58/reefski/?action=view¤t=anchorforpvcscreen.jpg" target="_blank"><img src="http://i93.photobucket.com/albums/l58/reefski/anchorforpvcscreen.jpg" border="0" alt="Photobucket"></a>
so the good news about that is i discovered it now before the sand went into the tank.
has anyone else had problems with their closed loop intakes?
the other bad news today is that i found out i am an idiot.
i had all the base rock in the tank pretty much where i wanted it. i made a funnel to put the sand into the bottom of the tank.
<a href="http://s93.photobucket.com/albums/l58/reefski/?action=view¤t=sandfunnel.jpg" target="_blank"><img src="http://i93.photobucket.com/albums/l58/reefski/sandfunnel.jpg" border="0" alt="Photobucket"></a>
i covered the closed loop pump intakes with a baggie and rubber band. we decided to take lunch before getting started so i turned back on the CL pumps. OOPS! those baggies were instantly sucked into the pipe and no water came out of the closed loops. i turned the pumps off within a couple seconds and started taking apart the pumps and fishing out the baggies.
fortunately they came out without any harm to the pump.
ran out of time to put the sand in. monday i hope.