Non-drilled Closed Loop?

[hyperfocal]

I'm thinking about ditching my mjmod and Seio, replacing them with a closed-loop (Oceans-motion driven). Right now, my tank is drilled for sump drain and return only, no holes for CL drain or returns so ideally I'd find a way to plumb it without holes. Drilling a drain hole is possible (drain tank to ~25%, drill from the inside) but I'd rather avoid it.

Of course the return is the easy part, just plumb lines off of the OM using PVC and locline through the top holes in the eurobracing... the tough part is the drain. I'd like to avoid any kind of siphon or manual priming scheme if possible, but I'm not sure I'll be able to. I don't remember seeing any self-priming pumps out there. Any ideas?

 

[dragon_slayer]

a Closed Loop doesn't have any form of siphon or priming required (other then bleeding the air the first time), it's CLOSED, the loop is not broken and the only way for air to enter the system is if it gets sucked in on the suction side (not a drain).

kc

 

[hyperfocal]

Right, I understand that. Without the water-pressure behind a drilled drain you'd have to manually prime the pump (say, for the first startup or after a power failure). It is that manual priming I'm trying to avoid.

EDIT: Though I guess you wouldn't lose the priming after a power failure, would you? So really, the only priming needed is the first time. I could probably live with that...

 

[rob28]

even after a power failure the closed loop dosen't loose it's prime once the innitial air is bled off when u start it up...

 

[smcdonn]

Indeed. I bled mine the first time and it has never been bled again. I can even shut it off and then turn it on hours later and it stays primed.

 

[Beach Native]

I built mine using this as a starting point (my tank is completely undrilled). I left off the priming section...just stick a piece of air hose into the setup and draw out enough air to get it primed. Once it's running, you'll neved have to prime it again (until you take it apart anyway).

As with anything else, putting valves in line helps with maintenance.

http://melevsreef.com/closedloop.html

 

[dragon_slayer]

I've never had a closed loop that didn't self prime as the tank was filled unless it has some elaborate elbows where it entered the tank that prevented the air from self purging. and once it's purged the first time you can leave it off for yrs and it'll still be primed unless you pumped air into it.

kc