Refugium pump question

[Dpaulmann]

Hello! I have a 65 Reef thats been setup for about 5 years now and I'm adding a refugium to it to help with algae control. The way the tank is setup I can't put anything underneath the tank so I'm making it in my basement. I'm making it out of stuff I've accumulated over the years. The refugium will be in a 29 gallon tank and there is 10 gallon tank for the return. I'm using an Eshopps 300 overflow box for the drain which leads me to my question. Everything is up and running well but I have a big bubble in the U tube that comes back right away whenever I suction it out which I believe tells me the pump is not strong enough. I'm very worried I will lose suction leading to a big mess. I found a website with a pump head height calculator and after I entered in the lengths and widths of the PVC as well as corners and ball valve info (The pump I'm using is a Mag 12) I figured the GPH is 196, the Mag 12 is rated at 1200 GPH. Do you think thats the reason for the bubble? Should I get a stronger pump? I do have an extra Mag 9.5, can that be added to assist with the flow? I have a guy thats h assisting me with the setup but I can't get him to call me back. FYI: The PVC info is 12.7 feet vertical, 4.2 feet horizontal, (9) 90 degree corners and 1 ball valve. I'd like to drain the tank down a bit, just drill it but I'm nervous I'll break the tank having never done that. Any advice?

[slitherbomb]

You need a HUGE return pump for something like that. More like 4000gph or something close.

[Dpaulmann]

Any suggestions on make or model?

[slitherbomb]

No, sorry, I'm not really good with naming models but I'm sure a quick google search will help you find what you're looking for.

[kdogg85]

Drain the tank completely, even some water is putting stress on the glass, and if you drill a hole, you will send a shock that may break it.

As far as pumps go, you may want to look into iwaki and little giant. If you are rich, you could check out the red dragon pumps.

That bubble is an indicator of low return flow. If the bubble instantly returns(if I interpreted right?), I would go ahead and shut off the pump if possible, you will have a flood in no time flat.

[Dpaulmann]

Thats good advice, I'll probably end up drilling it. I did call Eshopps and they told me that setup requires 195 - 325gph to work properly. As I mentioned I figured the Mag 12 was doing 196 which is according to them right at the bare minimum of flow. (If I calculated right). I do have an extra mag 9.5 that I could add as another return line. Do you think I'm wasting my time?

[melosu58]

Moved to General hardware and equipment discussion.

[kdogg85]

No if it is rated for 300gph,it is best to stay within 5gph. If it is kept at full load, the bubbles will never become a problem. You have around 17ft of pipe to push through plus the elbow and valve make for more restriction. Look around at what pushes 300gph or preferably 10 or 20 gph more. Put a valve on the outlet and slowly adjust it down, it will take a good chunk of time due to watching the water level overwhelm the overflow. I have learned this the hard way, it stinks to find out. Trust me.

[Dpaulmann]

Thanks so much for the good advice