Non Plumber wondering about refugium plumbing

[sixline]

So, about five years ago I bought my first reef aquarium and it has been running successfully and is somewhat well established. Now I want to add a refugium.

The tank is a Red Sea Max s400, which is a prebuilt and configured system. It has a mid sized sump that is full with a protein skimmer, return pump, and a media tray which I use for purigen, etc. The tank water drains by gravity into the sump, and then the return pump returns the water into the display tank. If there is a power outage, the return pump stops, water drains my gravity filling the sump, but there is no water on the floor! This is the level of advancement I have achieved in understanding reef plumbing over the course of the last five years.

The literature for the system said it was "refugio ready" whatever that means. The tubing through which the water drains into the sump has a Y connector and valve, allowing it to also drain somewhere else. This is intended to be used for a refugium. I have space remaining under my tank in the display stand where I could place a 10g or 20g tanks to be used as a refugium. And, or course, I could open the valve on the Y connector and drain water by gravity into the refugium. But how do I prevent it from overflowing and ensure that there is a slow flow back into the main display (or sump) to introduce copepods and amphipods to the display?

Alternatively, is there another way to get water to and from the refugium without risking leaks aside from using the Y connector?

Any thoughts, comments, or concerns are appreciated!

 

[DaveK]

You generally need to plumb the refugium with the same sort of overflow as you have on the main display tank. Since the flow through a refugium should be slow, the overflow can be smaller and less complex than the one on the display tank.

If you want the refugium to be primarily for additional filtration using macro algae, then it can drain back into the sump, along with all the other water. If you want the refugium to be primarily for pod production, then the first choice is to locate the refugium above the display tank and have the overflow from the refugium drain directly into the display tank. The next best choice for a pod producing refugium is to drain it back to the return pump section in the sump.

If you are going to add a refugium, make sure it's of decent size. The 10 gal one your considering would do some good, but you'd do a lot better with the 20 gal one.

 

[Squatch XXL]

But how do I prevent it from overflowing and ensure that there is a slow flow back into the main display (or sump) to introduce copepods and amphipods to the display?

Plumber here:

I have piped in additional tanks from time to time for frag tanks. I will refer to them as a refuge from here on out.

I keep my refuge BELOW my display tank, but ABOVE my sump. I run my drain pipe to the refuge, then a drain from my refuge to my sump. It is imperative that you have a refuge that is setup for this. For me to do this, I had to be able to regulate the drain line from the main tank to branch off (you said you have a "Y" pipe). I would reccommend a valve on either side of your drain so that you can regulate flow to both your refuge and your sump. The refuge basically acts as a second tank, and the physics are the same. This does not require an additional pump, as gravity is feeding the refuge then. When the power goes out, you still won't have an overflow because the amount of fluid that is in motion really does not change...(This is important to keep a dry floor)



In this photo, I have a frag tank beside the DT. You can see One of my 2 drain lines "Tees" off and goes all the way to the far right where it supplys my frag. Then the frag tank has a single drain line installed that dumps right back to the sump.

I hope this is not too complex of an explanation.

An alternative method would be to treat your refuge as another tank, and get a second pump and push water from your sump to the refuge, and let it drain back to the sump. this method however introduces more water in "motion" and can increase volume in your sump on power failure.

A 3rd method which I do not advise, but works. Put a small piece of tubing from the back of your tank, and create a siphon to feed your refuge. Gravity will drain to the refuge, and then to your sump.....however, this will take away from the amount of water that is going down your overflow drain. A power failure could drain the tank as low as the hose goes in your tank...once siphon is broke, it would need restarted.

A final method would be to keep the refuge above the main tank, and pump water from the sump or main tank to the refuge and have gravity drain it back to the tank. I don't like this method because it takes a bit of work to keep air bubbles from getting into your display. This method will also have more water "in motion" that will cause high water in your sump.

I hope this is not overly complicated.

 

[sixline]

Complicated for my little brain, but not overly so. I now understand the concepts well from your clear explanations, which was my goal in starting this thread. I will have to think a bit more before deciding whether to proceed, and if so, which method to use. Thanks to both of you!

 

[DaveK]

...
I keep my refuge BELOW my display tank, but ABOVE my sump. I run my drain pipe to the refuge, then a drain from my refuge to my sump. ...

I have to question this arrangement when used for a refugium. It's real easy for the refugium to turn into a settling tank and trap a lot of dirt that you really want picked up by the filtration system in the sump. It's that kind of thing that will work, but I think things can be done a lot better.