[newsaltfan]

So I’ve been running this type of overflow for about 12 months now…. First off let me say I’m a Chicken $hit when it comes to gambling with water on my wife’s carpet. Redundancy is my middle name. I run two 1 inch drains on a piddly 20L. I have tested things and a single overflow handles the volume I introduce into the tank.

Nothing is perfect…

Syphon failures….
In the 12 months I have been running the dual overflows I have had the same 1 of the 2 fail twice. The first time it failed I simply restarted it (by removing the air from the inverted “U” that transitions the overflow from the inside of the tank to the outside) and viola back in business. Never attempted to determine why it failed. So after the second failure on the same overflow I wondered what the issue was compared to the other overflow. Well apparently the one overflow was terminating barely above the waterline in my sumps filter sock and as the filter sock clogged the water level would rise and cause back pressure resulting in the loss of syphon. Well at least that’s what I figured. Since determining this was likely the issue I cut an inch off that drain and no issues. The other drain was already shorter.

Now as for the check valve mentioned in the YouTube video… sure it works but remember the C.$. from above I don’t trust a $2 fitting from the LFS especially if you aren’t running 2 overflows for redundancy…. I drilled and tapped holes for ” http://www.lowes.ca/pipe-fittings/watts-pl-3008-14-quick-connect-x-18-mip-90-elbow_8780434.html&linkloc=cataLogProductItemsImag e “ and added “ http://www.lowes.ca/valves/watts-pl-3011-14-pvc-compression-coupling-valve_g1194532.html “ this in line. I realize this adds a few dollars to the DIY build but worth the costs in my mind. And these fitting can be reused on other projects if these ever get torn down.

At one point I did try and plumb these, let’s call them bleeder valves, to the intake of my return pump but I could never get enough pull on the ¼ inch rigid water line used with the above fittings. I figure a larger return pump would solve that but I am already running a Mag 7 on a 20 L tank.

Once a month I manually purge any trapped air. Better safe than sorry.

I’m by no means an expert but if you have any questions ask away.