Cold Water Refugium Idea

CastAway · Jan 19, 2016

While standing in front of the refrigerator at my lfs, and contemplating the pods they keep refrigerated, I wondered why a person couldn't keep their refugium at a significantly cooler temperature than the display, and if there would not be any benefit for refugium fauna, flora and subsequently the display tank inhabitants in general.

Of course there would be some strategy regarding refugium throughput and chiller/heater locations, but I'm sure it could be done.

Thoughts?

Rob.D · Jan 19, 2016

Most coolers run around 34-40 degrees f, other than commercial lobster tanks, I don't think there is a feasible way to chill water...plus the effect of running 40 degree water back into a 80 degree tank just doesn't sound.....well....sound....

CastAway · Jan 19, 2016

Rob.D said:
Most coolers run around 34-40 degrees f, other than commercial lobster tanks, I don't think there is a feasible way to chill water...plus the effect of running 40 degree water back into a 80 degree tank just doesn't sound.....well....sound....

With a small enough volume being returned into the tank, and heating it before hand, you could minimize the cooling effect on the display - chill the refugium, heat the return, and run the display normally.

I think there's typically abundant life in the ocean where cold upwellings and currents meets warm water. Not sure if that happens near reefs however.

For the majority of the year, my fan is cooling my tank anyway.

melev · Jan 20, 2016

I don't see this working at all. Keeping our tanks a stable temperature is important. You are talking about heating up the cooled water. What about the 'warm' reef water going into the refugium all the time? You've have to cool that as well. Sounds like more electricity consumption both directions.

mcarroll · Jan 20, 2016

I imagine it's possible physically,...but it's hard to imagine many (any?) of the organisms from the cold water sump making it up to the (+50°F) warm water display and remaining in healthy shape.

Would there be another point besides this?

cmcoker · Jan 20, 2016

I thought the point of the refrigeration was to slow their metabolism, reduce wastes, etc., not really to promote growth or anything..

Sabellafella · Jan 20, 2016

I kno a chinese restaurant who has a jelly tank plumbed into their display. Feeds water threw a chiller system very slowly into the jelly tank, then its heated and back into their regular dt, i guess it couldhappen but their regular dt runs at77° and the jelly 65°. Beside the lfs keep the pods refrigerated so they metabolize less

mcarroll · Jan 20, 2016

cmcoker said:
I thought the point of the refrigeration was to slow their metabolism, reduce wastes, etc., not really to promote growth or anything..

I don't know why you would want this characteristic in your refugium though. [emoji6]

Randy Holmes-Farley · Jan 20, 2016

CastAway said:
I think there's typically abundant life in the ocean where cold upwellings and currents meets warm water. Not sure if that happens near reefs however.

.

It not the low temps that drive the growth at such locations in the ocean, but the nutrients in the upwelling water.

cu455 · Jan 20, 2016

If you chill the sump, put a heater in the display and use low flow it might work. I can't really imagine it having any advantages. The pods are in cool temps because they are dead and need to be kept at lower temps to prevent decaying or they are alive and this will slow down their metabolism and put them in hibernation.

Rob.D · Jan 20, 2016

cu455 said:
If you chill the sump, put a heater in the display and use low flow it might work. I can't really imagine it having any advantages. The pods are in cool temps because they are dead and need to be kept at lower temps to prevent decaying or they are alive and this will slow down their metabolism and put them in hibernation.

Actually, the refrigerated pods he is referring to are tigriopus californicus, this species of copepod are from cool waters and are sold alive.

CastAway · Jan 20, 2016

Hmmm. I did not know the cooler temps were to slow metabolism. That does change things for me. Makes me wonder about cold upwelling "nutrients". I thought those were the flora and fauna.

cmcoker · Jan 20, 2016

Rob.D said:
Actually, the refrigerated pods he is referring to are tigriopus californicus, this species of copepod are from cool waters and are sold alive.

Yes but can easily live and reproduce in 77° water, it is a shorter maturation and life span
"For example,
T~ californicus
000
achieves reproductive maturity in 32 days
at 15 C. but at 20 C. needs 27 days and 25 C. only
18 days. Longevity is also influenced: 129 days at
150 C., 116 days at 200 C., and 85 days at 25 0 C. (Vittor,
1971)."

De Michieli · Jan 20, 2016

I think the only way you would be able to do this would be with 3 sumps. Water coming from the display hits the cooler(first sump). Then goes to the second sump (pods) Then hits the 3rd with the heaters. The thing is your going to need way over sized heaters and coolers to be able to do this in that short period of time as the water passes. To the point I dont think it would be feasible / economical.

redfishbluefish · Jan 20, 2016

Wow! I'm having a tough time wrapping my mind around this one. It reminds me of perpetual motion machines. As mentioned, energy consumption, flow rates, total temperature drop.....and for why? Also, what about thermal shock as stuff goes for warm to cold to warm.

I think if you want a cold water nursery, set up a 2.5 gallon tank in one of those little cube refrigerators. Energy wise, it would be much cheaper......and doable.

Randy Holmes-Farley · Jan 20, 2016

CastAway said:
Hmmm. I did not know the cooler temps were to slow metabolism. That does change things for me. Makes me wonder about cold upwelling "nutrients". I thought those were the flora and fauna.

Those upwelling nutrients are things like iron, nitrate, phosphate, other trace metals etc. That's at least partly because there are no creatures deep down that are consuming them, while there are dead organisms that settle to the bottom and decay.

CastAway · Jan 20, 2016

Well, the idea has fallen apart for me, but, I would not necessarily care about thermal shock as the only intent would have been to introduce fauna and flora into the DT to be consumed, not proliferate as in the cool refugium. And, in my mind I had not anticipated 40 degrees, but maybe 60.

The whole idea falls apart if fauna and flora don't really benefit from cooler temps, and cold ocean upwellings are more of an elemental nutrient source only and not biological.

mcarroll · Jan 20, 2016

Randy Holmes-Farley said:
Those upwelling nutrients are things like iron, nitrate, phosphate, other trace metals etc. That's at least partly because there are no creatures deep down that are consuming them, while there are dead organisms that settle to the bottom and decay.

I don't have the link handy, but supposedly whales are historically responsible for moving truly incredible amounts of nutrients from the deep ocean to the surface waters by feeding down deep and pooping up high. (whales are at historically low population levels, so it's hard to say what the picture looks like today.)

Randy Holmes-Farley · Jan 20, 2016

mcarroll said:
I don't have the link handy, but supposedly whales are historically responsible for moving truly incredible amounts of nutrients from the deep ocean to the surface waters by feeding down deep and pooping up high. (whales are at historically low population levels, so it's hard to say what the picture looks like today.)

I guess that would be called upwhaling.