my refuge setup and overflowing struggles

Hey y’all. Here is my long-winded story of trying to setup my refuge and a few snags Ithat ’d LOVE some help with.

My equipment/setup:
46 gal bow front
Quiet One 2200 pump
About 45” of head
Eshopps 300gph overflow box
Homemade 17gal capacity/12 gal operating .220” acrylic refuge box (26”x10”x16”) – skimmer left 4.25”/return middle 8”/refuge right 12”
1” ID vinyl tubing for down flow and return flow
Down flow is Teed off at the refuge box to separate flow to the skimmer and refuge sections
Ball valve on refuge side only of down flow
Ball valve on return flow after pump


Setting up the siphon
Initially I had a hard time getting much down flow because a large bubble was stuck in the top of the u-tube, but finally got it out by temporarily taking off the overflow box to allow better positioning of a small air hose for me to suck the bubble out. The low flow in the u-tube wasn’t enough to flush that bubble out, like most on the forums suggested it should. I later found that when I removed the two black sponge pre-filters that came with the overflow it would suck more water than the skimmer box could even supply and would quickly rid the u-tube of any bubbles. Well, that presented another problem—very loud gurgling from top of the small PVC pipe that pokes up out of the bulkhead. SO, once a high flow siphon was established I found that if I inserted the small black filter in the PVC pipe the suction would pull it all the way in and severely reduce flow again—out it came. Restart siphon. Okay, now if I fold it in half and place that on top of the PVC pipe it eliminates any and all noise AND reduces flow by only a little. GREAT!

Matching flow with pump and siphon
This has also been a little tricky. If I remove that small folded-in-half filter in the overflow drain box, I can turn the pump return valve to about 95% before it starts to drain my return box and the overflow/u-tube can’t keep up. When I then put the skimmer box back on that then became the weekest link and it couldn’t keep up with the flow and the u-tube inlet would start to gargle because the skimmer box would empty. So, I took my new Dremel Trio (thanks Babe) and cut a few more drains in the overflow box to help increase the amount of water than can flow in to it. It seemed to help and can keep up with about 75% throttle now. I thought I had the flow matched well while I was starting to type this out and looked over and my DT was about 2mm from overflowing, so I have since turned it down a smidge.

Safety/failure testing
For the record I’m extremely paranoid about flooding and water damage. Our tank is on the second floor of our new house and any “incident” would have almost certain disastrous and costly results.

I started with the power outage test. I have about 5 gallons of overflow capacity over the normal refuge operating level. I turned off the pump and the tank drained back in the refuge and stopped about an inch before the top after hitting the relief hole drilled in my return outlet spout. I plan on drilling 1-2 more holes once I determined if it was in the proper placement. So I suppose this test passed, or so I thought.

I then flipped the power back on and water looked and sounded like it was flowing again and I checked a text message. Well about 10 seconds later I looked up and HOLY **** my DT was about to overflow. I kill the pump and allow most to drain back in the return area. I turned the pump back on and sure enough, it’s pumping water back in faster than the siphon is pulling it out. What the heck, it was JUST working. So I go to my overflow box and see a good amount of bubbles stuck in the top of my u-tube again. Darn you bubbles, darn you. Once again, the flow was not high enough to pull the bubbles out and couldn’t keep up with my return pump. I reach in and pull out that aforementioned folded up black pre-filter and WOOSH. The flow increased and pulled all bubbles through like it was no problem, but back to the sucking, gurgling and flushing noises though—grrrr. So to sumarize, my DT will flood over because the siphon cannot resume the same flow level when the power comes back on if I leave that black filter in there, but if the filter is removed, it’s louder than a flushing toilet. NOT gonna pass inspection from the fiancé.

I then calculated that 2” of my DT would contain the return area’s volume to prevent an overflow (assuming no leakage from other chambers within the refuge), but that would put my water line well below the plastic trim on the tank and would look like complete butt. So this is almost not an option..

In conclusion, my biggest problem is my display tank overflowing from the quiet siphon not being able to keep up with the pump. If I take out the black pre-filter, the siphon resumes from a power outage fine, but is LOUD as can be.

Thoughts?

This whole project has come in about double my original budget, so I'd really prefer NOT to have to buy new equipment at this point if possible. I've attached couple pictures. My water is still rather cloudy from the silt of my new sand. Also, please ignore the sloppy silicone job on the refuge baffles. My first try was very neet looking, but the small beads couldn't hold the water pressure and the baffles caved in, so I had to recalk them while it was under my tank and I wen't just a little overboard. And yes I used weld-on #4.

 

It sounds to me like you need to pump the air out of the siphon tube in the overflow. Mmm... is there someway you can find a small air/water pump, like a dosing pump, that you can somehow route into the top of that tube, or connect to the tube? It would then start sucking the air bubbles out, allowing flow to resume.

Use your ingenuity!

 

I have a small pump, but that suction only needs to be run for a split second. If it continues to run it would start sucking water.

 

Interestingly enough, as I was finishing my original post I heard a tapping noise and I looked up to see two large water spots forming on my ceiling! It must have started sometime around when I pronounced how much I don't like water damage.

Now that we have our entire supply of towels drying in preparation for tonight and several tubs and pots sitting around, I have a few minutes to enjoy a cold one and update about my tank setup. Edit: And now to add insult to injury, our washing machine started leaking while washing those towels used to soak up the roof leak. Lol what a day!

I watched a few youtube videos, particularly this one YouTube - quieting overflow box.mpg, and tried actually using the large cylindrical foam piece with the hollow center. I placed that over the pvc pipe and it quieted it down considerably, but still had that noise the video demonstrates getting rid of. I messed with the flex tube and couldn't get it to help so I started to stuff the thin piece of foam inside the middle cavity of the large piece--well it wasn't helping. I then started to slowly pull out the flex tube and all at once it got relatively quiet! So I tucked the end in behind the box mount and plastic rail of the tank. It also passed all stops and starts and would resume siphon just fine. I have noticed more air bubbles passing through the u-tube, but none of them are sticking at the top. I'll be sure to keep an eye on that. My next step is to probably put some kind of noise dampener on top to make it even quieter. Maybe something like this YouTube - 55 gallon fowlr update 8/29/2010

The largest source of nose is now from the skimmer side down flow exit in the refuge. It’s bubbling and gurgling like crazy!

Any tips for that?