Will my DIY fuge work?

[returnofsid]

So here's the deal. I want to install a refugium under my 46 gal bowtank. I've got a spare 29 gal tank that I'm not using. Instead of shelling out the money for a HOB overflow, or attempting to make my own and worrying about what'll happen if I lose power (water all over the floor is NOT a good thing), I think I'm going to drill the 46 a couple inches below the top. My plan is to drill the hole 2" or 3" from the top and about 3" from the left hand side. Then I'm going to take a piece of 6" ABS pipe and split it lengthwise. I'll then cut several slits (notches) in one end of the ABS. The slits will be just below the surface of the water. I'll install a bulkhead through the glass and use PVC to do all my plumbing. Just inside the hole, I'll put a 90 degree elbow aimed at the surface and then use a short length of pipe to raise up to just below the surface. I'll then cover up the PVC and the hole with the ABS. Does this sound reasonable so far?
Okay, now for the outside of the tank. I plan to put a T fitting just outside the tank with the upper end open to the air to cut down on noise. The lower end will dump into my 29 gal. I plan on dividing the 29 into 2 or 3 compartments. The first compartment will be where the water dumps into and will hold my Remora Skimmer. From there, I'll have a divider that goes just high enough to contain deep enough water for the skimmer to function properly. Then I'll have a bubble trap baffle and refugium. In the refugium, I'll have live sand, live rock and Chaeto. At the other end of the refugium, I'll have another divider. After that divider, I'll have a spot for heaters if needed and for a return pump. I only plan on drilling one hole in the main tank so the return will just spill over the top edge of the tank. I am planning on using a powerhead in the last compartment, attached to tubing for the return.
Now I've got several questions.
#1. Will this configuration keep the problems of the sump/refugium overflowing in the event of a power outtage? I plan to keep the water level low enough in the sump that if the power goes out and the main tank drains to the level of the stand-pipe, that the sump will be able to contain it all.

#2. I'm not sure I'm doing the baffle correctly in my head. The first divider would go from the bottom of the tank up to a level high enough to raise the water enough for the skimmer to function. The second divider of the baffle system would start at about an inch above the bottom of the tank and raise to just below the first divider piece. Then I would put another piece that matches the first. I think this would force the water to flow over the first divider, under the second and then over the third before spilling into the refugium. The level of the divider at the other end of the refugium would be a bit lower that the level of the divider just before the fuge. Does this make sense? lol.

#3. What size hole should I drill and what size powerhead or pump should I use to return the water to the main tank?

Am I at all on the right track with this set-up? I sure hope so because I have everything I need other than a hole saw for drilling the hole and possibly the powerhead...although I do have a couple extra powerheads. Please offer any advice or suggestions you can come up with. Thanks.

Oh and I also plan on having lighting on the fuge.

 

[Jaymeany]

I'm not a big fan of baffles.....personal opinion though. I would prefer to add a small plastic tank for a refugium that dumps into the sump. Perhaps a split overflow line? Your thinking seems sound. As long as you account for the volume of water sucked back into the sump you shouldn't have a flood. Good thinking and good luck!!

 

[Krish]

I'll put a 90 degree elbow aimed at the surface and then use a short length of pipe to raise up to just below the surface. I'll then cover up the PVC and the hole with the ABS. Does this sound reasonable so far?

Hmm...Are you going to seal off the top completely so you can't see in there anymore or get it there? Also, You may have a bit of trouble with gurgling noises with an open pipe sitting there for water to drain in. You may want to put the hole a bit lower and use a durso standpipe or something similar to quiet it down...Just a thought

Okay, now for the outside of the tank. I plan to put a T fitting just outside the tank with the upper end open to the air to cut down on noise.

If I'm understanding this correctly, this may cause noise I'm thinking, but not too sure. Hopefully someone will chime in on that

#1. Will this configuration keep the problems of the sump/refugium overflowing in the event of a power outtage? I plan to keep the water level low enough in the sump that if the power goes out and the main tank drains to the level of the stand-pipe, that the sump will be able to contain it all.

What will determine if you won't have a flood is (1) You need to leave ample room in your sump (by not setting the baffles too high) so that you will have sufficient play when the power is cut because the water will continue to drain down the overflow until the water level drops below it. (2) That you put a hole in the return spout to break the siphon when the power is cut other wise, the water will back siphon until the nozzle is exposed to air. Other than that, I don't see any other problems

#2. I'm not sure I'm doing the baffle correctly in my head. The first divider would go from the bottom of the tank up to a level high enough to raise the water enough for the skimmer to function. The second divider of the baffle system would start at about an inch above the bottom of the tank and raise to just below the first divider piece. Then I would put another piece that matches the first. I think this would force the water to flow over the first divider, under the second and then over the third before spilling into the refugium. The level of the divider at the other end of the refugium would be a bit lower that the level of the divider just before the fuge. Does this make sense? lol.

LOL...That is entirely up to you, but how I have mine is with the first baffle coming up off of the bottom (like you said) then from there...Well here's the pic

#3. What size hole should I drill and what size powerhead or pump should I use to return the water to the main tank?

As for the hole size, that would depend on how much flow you want to run through your sump. That question is debateable, but personally I like around 800gph. That way you give the skimmer time to catch the junk coming in etc. With about 800gph, you can get away with a 1 1/2inch bulkhead and plumbing which is what I am using on my cube...


As for how everything sounds...It sounds like you are heading in the right direction. I'm no expert on these things, but I figured I'd offer what knowledge I do have. I'd wait on the others to chime in as well to see what they have to say. Best of luck with your new project from Krish the guy

 

[mfinn]

On my last 4 tanks, I had holes drilled on the back upper corners, just like you are planning. The 90's are pointed up with a short piece of pvc pipe in the end and a little gutter guard in the pipe end at the waters surface to keep fish from going down the drain.
But I don't use any other pvc around it.
On my 180, I have 2 -2" bulkheads, one in each upper corner.
I would suggest the you not use a small one but go atleast as large as 1-1/2"
When it's that big, there are less things that will clog it.
I'll get a picture in a few minutes

 

[Krish]

Not sure if this pic will spark any ideas at all for you, but here is a picture of my overflow for my cube. I used an elbow pointing sideways with a strainer and since the plumbing has slimed up some, I can't hear any water going down it now

 

[mfinn]

Here is the inside and the outside.
The pipe in the tee has to go up higher than the water level in the tank and the cap on top needs to have a hole in it to prevent a flushing effect.

 

[Krish]

That's really neat Martin! I don't ever remember seeing it done like that before for an oveflow. Very cool to know

 

[Mauisreef]

Is that a glass tank Finn?

 

[mfinn]

I believe the answer to your first question is something you will just have to play with. Using a pipe on the 90 on the inside of the tank that goes up close to the planned surface of the water will drain very little water to the sump in case of a power outage. Which is good. That means you will have use of most of the capasity of your sump.
You just have to make sure your return pipe has a syphon break drilled in it near the surface of the water.
Your baffle system is very similar to what I have already in place in my sump now.
There is a headloss calculator on Reef Centrals homepage that will give you a little idea on different pumps and headloss.

 

[mfinn]

Is that a glass tank Finn?

Yes it is a All Glass 180 and there is another one at the other end of the tank. They are 2" pvc.

 

[mfinn]

The only down side to this system is, I have approx 2000 gallons per hour going through these and I do have some drain noise that you can hear when the tv is off and the house is quiet. But only in the area the tank is in. I use two external pumps during the day, but have one on a timer, that turns it off later in the evening and that does cut the water noise down alot.

 

[returnofsid]

WOW...lots of great responses and advice...thanks all. The responses brought up a couple more questions.

#1. Am I right in thinking I should have my skimmer in the 1st chamber?
#2. I understand what's being said about the T outside the tank being open to air. That will probably cause a gurgling sound. Might have to rethink that.
#3. What's this about putting a hole in the return line, close to the water line?? I hadn't thought about the fact that water would syphon back down the return line in the event of a power outtage. Where does this hole go and how large?
#4. I also understand what you're saying about having my stand-pipe too close to the surface. This won't allow for enough drainage of the tank. I'll probably want my out-flow a little more below the surface and keep the sump/refugium water level low enough to handle any problems.
#5. What the heck is a durso stand pipe? lol.
#6. 1 1/2"?? WOW...I was thinking probably 1". Guess I need to think bigger.

 

[Krish]

#1. Am I right in thinking I should have my skimmer in the 1st chamber?

That is debateable, but I like mine there to get all the junk as it enters the sump

What's this about putting a hole in the return line, close to the water line?? I hadn't thought about the fact that water would syphon back down the return line in the event of a power outtage. Where does this hole go and how large

This hole is just there to break the siphon when the power is cut to the sump. As the water drains back and the hole is exposed to air, it sucks in air which breaks the siphon which in turn stops the water from flowing down. It doesn't have to be a big hole at all. Here's a picture to show you what we mean




As for the prefilter question...I'll let Martin handle that one. He has more experience

 

[returnofsid]

Ahhh okay, I totally understand the lil' hole concept now. Hmmm, I was just going to use some kind of J or U tube...but I like the idea of that "spray" attachment. It would disburse water over a wider area.

 

[mfinn]

#4 I have the end of the pvc pipe about 1/2" below the surface(where I want the surface to be).

#2 On top of the tee is another section of pvc pipe and a cap on top. In the cap is small 1/8" hole. This will stop most flushing and gurgling.

#5 www.dursostandpipes.com
This won't apply if you drill the back wall.
#6 Bigger is better

 

[mfinn]

You might be able to see how close the top of the pvc pipe is to the bottom of the plastic tank frame. One of the reasons I suggested going 1-1/2" dia bulkhead is that this is a good area for algae growth. The bigger the hole, the less likely it will get clogged with algea, or a snail etc.

 

[mfinn]

This has been a very effective way for a bullet proof overflow system for many years. I have had only one problem in 4 tanks over the last 15 years and that was last year, when one bulkhead fitting started leaking after being in place for 7 years.
But I do have to say that my next tank, which is very soon , will be drilled on the bottom and I will use a durso stand pipe system.
The reason is I'm eliminating all possible sources of noise on my next tank. Drain, fans,pumps.
But for ease of use, the 90 on the inside is hard to beat.
hth

 

[returnofsid]

Does everyone understand what I meant with the use of the ABS pipe split in half lengthwise? It'll have notched teeth cut into the upper end of it, at the surface. It'll serve the purpose of hiding the stand-pipe/bulkhead assembly and also create a surface skimmer action....I hope. I hadn't thought about needing to enclose it on the bottom. Do I need to? I hadn't planned on it and had just planned on having it be long enough to hide behind some rockwork on the bottom. Hmmm, maybe I should at least put some kind of screen on the bottom to keep fish from swimming up it...although I can't imagine they'd get stuck. Oh, I'm also planning on putting a strainer on the intake side to keep things from clogging up the system and to keep fish from getting flushed through it.

 

[nano_reeflover]

Hey instead of having the PVC elbow pointed upwards, have the opening facing the bottom of the tank. Keep the T on the outside and have the top "silencer" part go higher than the water line and have a small hole drilled in the cap. It will be much quieter.

 

[burning2nd]

Well krish hit it right on the head there boy, heres a few pic of my setup, i havent had any problems at all...... that little black tube thing that goes on the outlet side (into) the main tank is a MUST, also i dont know if it was said yet, but a power head will not move enought water for you quick enough up a tube,

theres a way of calculateing the head lose (water fighting gravity) usely onthe back of boxs for powerheads.

pre filters... i stand a a ferm negative on that. put it this way if a fish or a snail wants to go on a tube dream let me, your gonna find em in the sump,

the prefilter catch stuff build= no2 factory (i learned quick) it didnt take long a couple of days.

AQUA lifter, if you makeing your own (overflow) you must factor in a aqua lifter, these little things are the key,

but it seems your going with the drilling, keep in mind deserbing a tank thats exserting PSI on the glass or aclillic might get nasty

"Dont hate appreciate"

Yes that is my custom ziptie

also that sponge isnt there anymore