Bulkhead overflow questions/options

hansmatt

New member
I have three acrylic tanks stacked with a single eheim 1260 from the bottom/sump to the top. Each tank has 1" drilled bulkheads on the back edge (not bottom) that is plumbed with 1.5" pvc to the "return" of the tank below it. The bulkhead has an attached T (actually a sloping T, not straight drop, to make it quieter) with a cap fitted on the top (undrilled cap as of now). The problem I'm having is my return (eheim 1260) has a greater volume than my bulkheads are pushing. Yes, I can dial down the return with a T & gate valve, but would prefer not to. I'm looking for ideas on getting better flow through the bulkheads, quiet flow if possible. I initially had a 90 elbow pointing down, then sideways, then no fitting...I'm wondering if the lack of head/water pressure is giving too small of a push down the overflow?
 

RokleM

Premium Member
At 0", the 1260 should be pushing roughly 635 gallons.

Before we go into flow charts, blah, what do you have in the acrylic tanks? Do you NEED more return flow? Is it a big deal to throttle down the pump? Most importantly if you do want that flow, will your location and design allow you to just install some larger bulkheads (piece of cake to do since you're working with acrylic tanks).
 

hansmatt

New member
I'm at around 5.5" head, so I figure perhaps 400gph, but I agree that that's beside the point. The amount of flow would be fine (growout) but I may have a powerhead too...I would think that a 1" bulkhead would handle 400gph, and the 1.5" pvc is more than enough. Is there a way to increase the fow through the bulkhead withough replacing it...I may simply dial down the pump if there is not another easy way.
 

RokleM

Premium Member
To maximize the flow you can either 1) create a force siphon (potentially dangerous), or 2) ensure you have the least amount of restriction possible. That's using a 1" bulkhead with the "widest" internal hole, removing all 45 or 90 degree bends (see if spaflex bent is possible), ensuring the bulkhead filter has little to no flow restriction at all, etc.
 
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