[CaptainK]

Hi Everyone,
I am now planning to make an overflow using the directions from the following web site: http://www.reefs.org/library/diy/diy_winner1.html
I have a few questions:
1)In the outside box should should there be a divider put in to split the box in two? I think I saw some other overflow boxes with this because it is suppossed to keep the siphon in case of a power outage. Is this correct?
2)The airline tube that is used to start the siphon, can I assume that one the siphon is going that that airline tube should be closed?
3)Lastly, should I be OK with just using super glue instaed of the silicone sealent stuff? If I do have to, or should, use the silicone stuff which should I get.

Thanks,
CaptK

[Reefland]

Making these can sometimes be tricky, other times they are no problem at all.

1. A divider can be used to keep the section of the outside box which has the U tubes in it with a steady level of water. This helps with keeping the siphon during a power outage and can keep the siphon running at a consistent pace (if the water level is flucuating where the U tube is in the outside box, it could slow the siphon depending on the water pressure it is trying to push through).

2. Putting some type of valve would be a sure way to make sure water won't come through it. If you put a valve into the U tube itself, you can hook up the tube and open the valve as needed. On the other hand, if the overflow is made correctly, you shouldn't have a need for this anyway. It can be easily bypassed if you want to start the siphon by sticking some airline tube inside of the U tube to get it started initally, or even use a powerhead.

3. I would stick with silicone. You can find some aquarium grade silicone at the local pet shop typically or look at Home Depot or other comparible hardware store.

Good luck and let us know how it turns out!
Scott Z.

[dattack]

Captain ,
How much money would you save making an overflow like this? It probably cost around $20 to make this overflow and no guarantee it will work. Learn to work with some small pieces of acrylic and in the long run you can save a lot more money making it out of acrylic sheets.

Once you learn to work with acrylic, you can pretty much make everything cheap. Have your local plastic store precut the pieces for you and you can glue it together with weldon-4.

[afishybusiness]

The L (90) inside the box (if it is positioned above the lowest part of the Utube) will keep you from having to make a divider. If there was no 90 and there was just a hole in the bottom of the box, you would then have problems getting a siphon after the power comes back on. The airline coming out of the top of the U is best placed on the venturi of a power head. In wich case, if the other measures fail, when the power comes back on, the venturi sucks air out of the tube and the siphon is restored. You would of course want to make sure that the airline is VERY secure on the powerhead to prevent an unwanted siphon (onto your floor). Hope this helps.

[CaptainK]

Thanks for the help guys, I cannot beiieve that this stuff is actually making sense to me.....at the moment.
What is the "venturi of a power head" on a powerhead?
Also is there any particular name brand that I should stick with when selecting the silicone?
I would consider building my own things but I think I should take some baby steps first

[afishybusiness]

The venturi is the item that introduces air and mixes it with the water being pumped through the powerhead. The venturi traditionally goes on the outlet of the pump and is often something that can be clipped on (or off). One doesn't really want air in their reef, but once the air is out of the overflow, there is no more air to introduce. Due to it's air sucking capabilities, it is perfect for restoring the siphon. Much of this stuff is common sense. A guideline that has helped me in the past is to always keep in mind that water finds it's own level. If you keep this in mind, most of the other stuff falls into place. Now when you start talking about what diameter for what flow rate, and all of that.. I'm right there with you! Have fun!