PDA

View Full Version : more simple overflow box



mkiiisupradude
10-05-2010, 08:25 AM
Ive been doing alot of looking around and cant seem to find anyone who has tried this. why do you need an overflow box inside the aquarium as long as your syphon does not break? I plan to run a tube to the bottom of my tank, then out the top into a very "conventional" overflow box. I figure as long as the drain is at the desired water level, and the tube is below on both ends so that the syphon doesnt break, why should i need an ugly box in my aquarium with my beautiful fish?
Am I missing something here??

Michael Milligan
10-05-2010, 10:22 AM
Am I missing something here??

yup, the main idea is in the even of a power outage. Then it drains to that point and stops. Which is true in a simple siphon however in the a regular siphon drain the siphon will break when it hits the low point, an proper overflow keeps the siphon. So, when the power comes back on it is business as usual. If you only have a siphon then the return pump will kick in and empty your sump into the main tank while the main tank won't drain. BIG problem.

Crispy
10-05-2010, 11:29 AM
+1. You could easily lose siphon when the water level gets too low and then your pump will drain your sump and flood your tank/floor. It's not a good idea when you really think about it. Search for a DIY pcv overflow if you don't want the box in your tank.

mkiiisupradude
10-06-2010, 01:56 AM
ok, sorry if i wasnt clear, it was pretty late when i wrote that, but the point of 2 boxes is to have a water "level" between the 2 that can not drop so as to let water exit the tank in a controlled manner that wont continue if your pump fails. What i am saying is a hose from a traditional box outside the tank runs into the tank as low (deep) as you want it. the only trick is the box outside has a raised "drain" at the level you want the water in the tank at. the hose from the tank will of course be below that level on both sides thus maintaining the syphon. ergo the syphon hose equalizes the level of your tank and the outside only box and when the level in the tank rises the level in the box rises thus overflowing the way a typical stand pipe would. this would allow you to syphon water from lower in the tank where you need it (colder dirtier water) unlike a typical overflow box. it would also make the system more simple and cheaper as well. if your pump shuts off it of course can have a syphon break hole in the system if you arent using a spray bar and obviousely it is self priming so it does not backflow to your sump. hopefully that was said better this time lol.
in short the "stand pipe" in the outside only overflow box regulates the water level and the syphon tube is lower both in the tank and in the box.

Michael Milligan
10-06-2010, 09:58 AM
This?


http://i188.photobucket.com/albums/z116/Globalist1789/overflow.jpg

I built one like that before. The back was maid from a plastic measuring cup hanging on the back by its handle! Prototype. hehe

Piscine
10-06-2010, 08:16 PM
I like the idea as far as aesthetics go, but I like my surface skimming overflow.

mkiiisupradude
10-08-2010, 02:57 AM
i was begining to think my english was bad. Thats exactly it. Why is that not more common? I mean I havnt even seen one before and i was looking pretty hard

Fishguy2727
10-08-2010, 03:12 AM
Surface skimming is very important, especially with corals. I would prefer the black box I have on the inside of my tank over a pipe, the pipe would stand out much worse.

Water changes are usually when you lose your siphon. Unless you drain out of the sump you will ose your siphon every water change.

That design on the inside of the tank is exactly how DIY overflows work.

Michael Milligan
10-08-2010, 03:22 AM
Good thing I drew that pic! lol

It wouldn't skim as suggested above. Any proper circulation would prevent water lower in the tank from being any dirtier.

Was also a pain to build and prime compared to other designs.

mkiiisupradude
10-08-2010, 06:59 AM
I wouldnt know about salt water set ups. My purpose is to cycle a 55g from top to bottom with as little current as possible (lake cichlids) and still get the best "cycle" per hour possible.
As far as priming I cant see what would be different. Even durring a water change, the whole system could stay running. and as far as building it, its litteraly half the system with a longer hose...

Michael Milligan
10-08-2010, 10:00 AM
Since it was my first build, mine sucked to prime (pun fully intended) because I made no allowance for it when making it.

No one is going to tell you that this won't work for you.

Piscine
10-08-2010, 11:13 AM
As far as priming I cant see what would be different. Even durring a water change, the whole system could stay running. and as far as building it, its litteraly half the system with a longer hose...

The system couldn't stay running because your sump would go dry and your pump would most likely overheat. You would have to turn off the system and restart the siphon, which would require refilling the "cup" on the back, and having a valve to suck the air out on at the uppermost part of the tube that goes over the rim of the tank.

As your water level drops during a water change, the siphon would reverse itself and cause all of the water to drain out of the little "cup" on the back, allowing air into the siphon pipe. If you need to avoid surface disturbances for a planted tank, best to go the canister route.

Sarkazmo
10-08-2010, 01:42 PM
You're trying to re-invent the wheel it seems. It's another design that does essentially the same thing. There's tons of DIY designs out there and they all basically do the same thing. Some designs are better than others though. No matter what way you do it you're still going to end up with something in your tank whether it be tube or overflow. Another advantage of using the overflow is that you won't lose the siphon no matter if you remove from the tank or sump. Without the overflow you're limited to the depth of the pickup for water removal and still keep the the siphon. In the illustration above you can only remove water from the tank until the water level drops below the outflow in the hob box as it'll draw the water from the box and break the siphon.

Sark

mkiiisupradude
10-09-2010, 01:49 AM
exelent point! thats why i was bringing this up, to trouble shoot. In the military nothing is ever clean unless someone else looks at it first.
The main reason i needed to figure out an alternative was to stick with hidding the plumbing. Ive already got a slot out of the back of my background for the hose to fit (before I understood the purpose of a box I was going to try to match the hose syphon to the pump with a ball valve. bad idea I know). luckily as long as the syphon only breaks while i am there changing the water I dont have to worry about power outages. Thanks for the help in problem solving this set up everyone!

Michael Milligan
10-09-2010, 02:00 AM
If your motive is to hide plumbing then go for an internal overflow. If your tank is empty, drill it. WELL worth it!

Fishguy2727
10-09-2010, 12:32 PM
Find my overflow box:
http://i28.photobucket.com/albums/c207/reptileguy2727/Reef/IMG_1223.jpg

kaybee
10-10-2010, 03:12 PM
Nice reef fishguy! :thumb:

mkiiisupradude
10-18-2010, 12:34 AM
Find my overflow box:
http://i28.photobucket.com/albums/c207/reptileguy2727/Reef/IMG_1223.jpg
that was extemely informative! thank you for your help!

mkiiisupradude
10-20-2010, 07:23 AM
just an update. silicone finished drying and system has been running for a couple days now. Ive got a pretty strong pump so for a while it seemed like the overflow would not work.
Then I had an idea, lowering the "leveling drain" on the outside box would increase the presure differential between the tank and said box, thereby increasing flow. worked like a charm and after a little tweaking the tube is about 2 inches below the level in the tank. no creep whatsoever in the level and the drain is keeping up just fine. as a matter of fact i turned the pump up more and the higher the level, the more flow I get through the 3/4 in tube. (probably common knowlege for most but maybe someone has a question about that as I was litteraly panicking and shutting off my pump before it could raise enough to keep up).
Power off tests work great and as long as I turn the pump off I am able to do aprox 50% water change and still maintane the syphon (the outside box is deep for this purpose! Thanks for the input on that piece!)
All together spent about $10 for the overflow and it keeps up nicely with my QiuetOne 2200 at 4 ft of head! If I remeber correctly, right around 400 gph im not sure as I threw the box out already. not bad for a 55g though and the flow is still not too fast over all being top center on a long spray bar.
Thanks again for the help!

BarbMaster
10-20-2010, 08:09 AM
Find my overflow box:
http://i28.photobucket.com/albums/c207/reptileguy2727/Reef/IMG_1223.jpg
upper left corner on the top rock

Michael Milligan
11-21-2010, 09:25 AM
just an update. silicone finished drying and system has been running for a couple days now. Ive got a pretty strong pump so for a while it seemed like the overflow would not work.



Only just saw this post, sorry.

This is why I put a ball valve in my return line. Then I can control the flow if I need to.

Sarkazmo
11-21-2010, 10:56 AM
Only just saw this post, sorry.

This is why I put a ball valve in my return line. Then I can control the flow if I need to.

You shouldn't use a valve on the return line unless it's a bypass valve that diverts water back into the sump. If you have a valve it puts extra back pressure on the pump, making it work harder than it has to.

Sark

Michael Milligan
11-21-2010, 08:06 PM
I suppose it depends on the type of pump. mine is the magnetic drive, so when the pressure exceeds the the pumps capacity then shaft wont spin. It's the only moving part. Switching magnets on and off is all the "work" the pump actually does, and that doesn't change based on back pressure.

Fishguy2727
11-30-2010, 12:09 AM
Using the excess flow to run something else (like a reactor) is ideal, dumping back into the sump is good, but as long as the valve is AFTER the pump it should be fine. It is when you restrict flow going into the pump that will really make it work harder.