drain lines, a complete summary

[jacksonpt]

I'd like to see a reasonably comprehensive reference source for the different drain lines/systems typically used in the hobby, along with the pros and cons of them, and how/where they are typically used. I think it could be helpful for someone looking to troubleshoot an existing drain setup, improve/overhaul an existing system, or someone looking at their options for a new system.

I couldn't find anything like this, but thought it might be helpful to get some of this information all in 1 place. It has the potential to pretty substantial, so I expect (hope) that it will grow and evolve, kinda like a wikipedia page, as people add their own experiences, hacks, etc.


I'll start with the little bit that I know, but since I'm looking to learn more than contribute, I'll leave most of it to the experts.


Siphon drain line

• Refers to a drain line that does not allow water to mix with air - the line is completely and constantly filled with water, never air
• Most commonly seen as part of Herbie and Bean drain systems.
• Pros - high flow rates, low noise
• Cons - requires some tuning based on return pump flow rate, usually needs a secondary drain line to correctly balance return flow and drain flow.

Open Channel drain line

• Refers to a drain line where water and air mix
• Most commonly seen in "reef ready" tanks that come with mega overflows, standpipes, glass holes overflow boxes, etc. Also used as a secondary drain line when a siphon is the primary drain
• Pros - Easy to setup, reliable
• Cons - can be loud, can lead to lots of splashing/turbulence/bubbles in the sump

OK, I turn it over to all of you... please run with it. If most of this is seen as common knowledge across the hobby, then just let this thread disappear down through the pages.

 

[jacksonpt]

One of the things I'd like to see come from this thread is how people have addressed/solved some of the cons with these...

 

[Vinny Kreyling]

To avoid the waterfall effect in an overflow box I placed a piece of thin ABS with a reverse bend (backwards away from the teeth), in the shape of the box supported by the back ends leaving about 1/8 -1/4" space @ the bottom so the water flows against the box.
You have to fiddle some to make it right but it does work.

 

[mcgyvr]

To avoid the waterfall effect in an overflow box I placed a piece of thin ABS with a reverse bend (backwards away from the teeth), in the shape of the box supported by the back ends leaving about 1/8 -1/4" space @ the bottom so the water flows against the box.
You have to fiddle some to make it right but it does work.

And to go with the theme of this thread this is a reminder of what you may need to do if you don't think about mitigating the waterfall effect when designing your overflow box.. If the elbows are too low and the bulkhead or edge of weir is too high compared to the elbow then you get excessive noise..

Plan properly and you maintain the potential for "silence"

 

[jacksonpt]

That brings up a good point... There are 3 primary sources of noise in a drain system. Some are more common with certain systems/drain lines, some are not.

(1) water flowing into the overflow box (through bulkheads, over weirs, etc)
(2) water entering the drain pipe(s), most commonly a slurping or gurgling sound
(3) water exiting the drain pipe/entering the sump, usually splashing

All 3 are largely preventable/fixable.

 

[jacksonpt]

And that segues into a question I have regarding a problem I'm currently battling.

What's the best way to deal with splashing and bubbles coming from an open drain line as water enters my sump? It's my primary drain, so reducing flow wouldn't be my first choice. Since "best" can be relative, let me rephrase... what are some ways to reduce/minimize the splashing of water as it enters my sump from an open (water/air mix) drain line?

I've seen drummereefs bubble killer... but are there other solutions?
http://www.reefcentral.com/forums/showpost.php?p=17278505&postcount=1351

 

[nereefpat]

And that segues into a question I have regarding a problem I'm currently battling.

What's the best way to deal with splashing and bubbles coming from an open drain line as water enters my sump? It's my primary drain, so reducing flow wouldn't be my first choice. Since "best" can be relative, let me rephrase... what are some ways to reduce/minimize the splashing of water as it enters my sump from an open (water/air mix) drain line?

I've seen drummereefs bubble killer... but are there other solutions?
http://www.reefcentral.com/forums/showpost.php?p=17278505&postcount=1351

That's the limitation of open drain systems. (I'm sure you are aware, but some folks aren't). They can only handle low flows.

I did see someone recently recommend putting a tee fitting horizontally on the drain line right at the water level in the sump as a means to letting the bubbles escape and help with the splashing.