Neptune Aquatics

New member, building a coldwater marine aquarium

jonah427

jonah427

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I am a new member, happy to be here. I have been keeping fish since childhood and keeping reef tanks, off and on, for about 10 years. I currently have a Fluval 13.5 nano reef with a simple assortment of soft coral and LPS. In addition, I am a teacher and keep a 40-gallon low tech planted tank in my classroom.

My main project now is building a cold water marine aquarium. It's something I've been interested in for a few years, and I've been seriously researching and planning for a could months. I am fascinated by the temperate/cold water sea life nearby off the pacific coast, and like the challenge of setting up this kind of system.

I think it would be an interesting challenge for anyone, and in particular for me because the methods for cold water are diametrically opposed to my usual reefing philosophy for tropical. For tropical reef tanks- actually for any system, including freshwater, I like to minimize complicated equipment + mechanical filtration, and let the bacteria and plants do the work for me. I favor plenty of habitat for aerobic and anaerobic bacteria, and plenty of flow. In freshwater this means I always do planted tanks, and in saltwater this means a big and well-lit fuge and no skimmer. On the other hand, with this new project, biological processes happen slower in a coldwater tank, so mechanical filtration and skimming are more important.

A big challenge is finding a tank that will work for cold water. Most off the shelf glass and acrylic tanks will not insulate well enough, leading to condensation on the glass. For this reason thick acrylic tanks are pretty standard. After looking for custom aquarium builders and talking with several I finally struck a deal with Advanced Acrylics for a 36"x18"x16" tank made with 1" thick acrylic panels all around and 3/4th"thick on the bottom. That is 40 gallons and almost the same dimensions as a standard 40 gallon breeder. There is a 5" sump compartment, peninsula style on one side I will fill with bio balls and marine pure, and a thick sponge or two. The tank is currently being made and I expect delivery in about a month. In the mean time I am pulling together the rest of the equipment and beginning the long process of sourcing the very 200+lbs of sand and rock for my hardscape. I have ordered a JBJ 1/10HP chiller and two Tunze DC pumps that will be on the bulkhead (the 1" walls may be too thick. I am thinking about Kessil lights, and still unsure if I can or should be trying to get away without a skimmer.




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The facebook group "Coldwater Aquarium Owners" is an invaluable resource for anyone interested in cold water. I hope to continue to post here as I set up this system.
 
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Welcome. Sounds like a fun project!

Yes, powerheads will be no fun with 1". I have trouble enough with 3/4".
Tunze does sell an extra large magnet.
 
This will be an interesting tank. Looking forward to the progress. There are so many critters you can pick up during low tide...hermits, snails, crabs.
 
Oh, cool! I would love to set up a coldwater tank but I decided against it due to chiller, plus I'm kind of in over my head already with school tanks. So glad to hear you have a tank in your classroom - what level or subject do you teach? I teach 8th grade science and a section of aquatic studies elective. I was looking at a place in Oregon where another teacher got a coldwater tank for native species. I am very interested in following your tank build and I bet other members are, too. Welcome!
 
I have always wondered if a cold water tank uses more or less electricity than our toasty warm reef tanks.
On average, especially including night time, air temperature it pretty cool in the bay area.
Evaporative cooling with a fan is really cheap and can help several degrees.
But chillers are not that efficient, and really burn power when running.

When I turn my pool solar heaters off, it quickly drops to low 70s in summer. Much colder in winter.
 
MolaMola said:
Oh, cool! I would love to set up a coldwater tank but I decided against it due to chiller, plus I'm kind of in over my head already with school tanks. So glad to hear you have a tank in your classroom - what level or subject do you teach? I teach 8th grade science and a section of aquatic studies elective. I was looking at a place in Oregon where another teacher got a coldwater tank for native species. I am very interested in following your tank build and I bet other members are, too. Welcome!
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I teach kindergarten!
 
Rostato said:
I’ve always wanted to try cold water, but it just seemed too power hungry. I also worry about it getting too warm in my house
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Thanks for the comment! From what I have heard, chillers have gotten more efficient in recent years, and the extra thick acrylic should help as well. I have the benefit of having it in my classroom so I am not paying for electricity. If I get equipment to do so, I'll definitely report on the power consumption.
 
Update:

Thank you to all for being welcoming and for the replies! I see that the power consumption of the chiller is a common question: honestly, I am lucky to be able to set it up in my classroom so I don't pay myself for the electricity. Eventually, I'm sure I will bring it home (I'll have to for the summer, not looking forward to that move), and I'll get a sense of how much power it consumes.

I am still waiting for the aquarium to be delivered but feel I am making progress nonetheless. http://www.matsucollections.com has proved to be an invaluable resource and I am planning my first order from them- basically a clean up crew, a couple of gobies, and macro algae. I have fallen in love with the endless possibilities for rock aquascape- compared to tropical reefs, there is a huge diversity in possible rocks to use and I think that the look that this gives is awesome. Been trying to learn about aquascaping, very open to any advice or good resources for this.

Since my first post, I have continued to do research and it seems like biological filtration can and will play a bigger role than I initially thought. My previous thinking was that a coldwater tank would slow nitrifying bacteria and macro algae to such an extreme extent that it would be close to useless, and that I would be forced to rely on a big skimmer and a low-stocked tank. As I talk to more people, it seems that , while processes are definitely slowed, they can still play a role.

I watched a very interesting and worthwhile MACNA talk by the Dr. Tim that I recommend to all:

Right now, my biggest questions surround how to provide the macro algae with the conditions they need to thrive. There is a limited availability of cnidarians, so cool macroalgaes with have to do the heavy lifting in terms of adding interesting life to the display. I actually have a co2 system laying around and have been wondering whether it might be worth it to add it. I also wonder if i'll need to dose any nutrients. If anyone has any experience with salt water plants I would definitely appreciate advice on how to keep them happy.
 
Can you grow Kelp?
:)

Seems like my choice for macros would be to go to the tidepools locally, grab a bit of everything, and see what grows.
There is a bit of literature out there, but since all tanks are so different, experimentation may be your best bet.
And since it is basically free, why not.

Co2 may cause PH problems, so be a bit careful with that.
 
My last update on my coldwater tank was in November and can be found above in this thread. Time for a new one. It’s been set up a month and currently cycling. I'll go into sand, rock, the cycling process, and livestock in my next update- for now, just an introduction to my setup.

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It took me a while to get the tank up and running as I was ridiculously busy at the end of the year. I decided to set up the tank in a corner in my basement that mostly avoids natural light but is right next to a door for easy access to outside water spigots and drains. Advanced Acrylics did an amazing job, and I was thrilled to see the 36”x18”x16” tank I had ordered. Despite being 1” thick all around, the outside dimensions match that of a 40 gallon breeder, letting me use an ordinary Petco metal stand. I bought a smaller stand from the same company and added a couple panels to manage all the cords and controllers.

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At left we have a Kessil controller for the two A360 Tuna Sun lights. Because growing macro algae will be a key goal, the consensus from everyone I spoke to was that these freshwater planted-tank style lights were the way to go, as opposed to lights aimed for coral. Now, I am more confident than ever that I can source a variety of cool anemones, so algae will likely play a smaller role. I’m not a guy into super blued-out tanks, but even so I wish the lights could get a little bluer. Tuna Blue lights or ultra-controllable AI lights might have been the way to go. I’m not really concerned, they are fantastic lights producing wonderful shimmer and I can always throw them on a planted tank and get blue lights in the future if I so choose.

Next is a Ph controller. It’ll make setting up a CO2 dosing system (for macroalgae) a breeze if I go that route, although I don’t see myself doing that quite yet. The reason is the Ph is at 7.8-7.9. I have never been the type of person to arbitrarily chase numbers (I usually have only a tenuous grasp on what the tank numbers even are at any particular moment), but it seems to me that I wouldn’t want to risk going lower. If I saw the tank was stabilizing at 8.0 or 8.1 or so, I’d happy set up CO2 dosing to maintain 7.8, but if its that low just off the bat, I’m nervous about dosing C02.

Next are the controllers for the two Tunze powerheads. I’ve found them to be simple and intuitive, and they have served me well so far.

Finally, a wonderful piece of gear that I can’t believe isn’t more common- an Inkbird wifi-enabled temp controller. It has two separate rubber temperature probes, which I found to be very accurate out of the box by comparing to other thermometers. If you so choose you can plug in a heater, but for me I just have it monitoring, not controlling the chiller. More importantly, it broadcasts the temperature by wifi so I can see it by phone no matter where I am. I haven’t seen a lot of Inkbirds on reef tanks, so at first I thought they seemed to good to be true- something this good must have something that makes it unsuitable, or we’d see it way more. But Inkbird has a good reputation among home brewers and other hobbyists that use it more, and they are working with BRS to make the new BRS heaters. When I asked on the ‘Ask #BRSTV” if anyone had any concerns about the Inkbirds for a marine aquarium, the only thing that came up were the metal temp probes. Well, the particular model I used has rubber (or plastic?) temp probs, so no issue there. All told an amazing tool for less than $50.

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The chiller has served me well so far. No complaints. I have a pretty simple 300-something GPH pump running water through it with flexible tubing. I may experiment with insulating the tubing. I have a 400-something AC return pump salvaged from an old broken-down tank. Both pumps are in the third AIO-sump chamber and the chiller return line is into the main display in the corner near the regular return (or in the third chamber as it appears in the above pic? I don't remember). I have a Varios-2 sitting in a box at the moment- so far I have had no issues with the cheaper pumps. Thinking that the sand and rocks I'd use would have less surface area than typical reef rock, I bought two gallons of marinepure balls and 3 gallons of those old-fashioned black plastic balls. My original idea was to mix them together homogeneously to leverage the surface area of the marine pure while not stopping up flow too badly. Turns out the plastic balls kind of float (they won't go ABOVE the water line too much, but they'll tend to hang around the surface unless there are enough of them to keep them in place. So mixing them together is impractical but I have about 1.5 gallons of the marine pure and 2.5 gallons of the plastic balls in the various return chambers. Looking at it it looks like too much, but I haven't had any issues with flow through the sump or water level in the chambers. If I do, I'll probably be taking out some of the bio media. The only mechanical filtration is a little square of floss I cut out and kind of wedged in the overflow- I love microfauna and I want to give it the best shot- no skimmer and no filter socks.

Like I said, I'll go into cycling, sand, and rock, in the next update.
 

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Nice!
I would avoid those plastic balls though.
Seems like you have plenty of surface area.
And note that algae can use ammonia directly (in theory prefer it) so by going with plastic balls you sort of compete with the macro algae.
 
I will go into stocking later, but will not be collecting livestock myself. Some will be collected by Matsu Collections, which is licensed to collect and sell many types of local sea life. Other items - particularly anemones - will be sourced from Oregon, Maine, and elsewhere consistent with state collection laws.
 
Very nice write up so far!

I use InkBird controllers (2) as backup safety controllers for my 2 heaters. I’m happy with them, but certainly not needing to use them to their fullest.

I agree the plastic balls are of questionable value, and probably a waste of space. Being totally honest, I never really understood why people used them, even back when they were popular. I get that they are surface area for bacteria, but you already have a lot, and any porous rock like we use for reefs or those MarinePure balls you have will have 1000’s-fold more surface area per volume. Each one of those MP balls probably contributes more than all the plastic balls combined. I’d just remove the plastic balls personally.
 
jonah427 said:
Next is a Ph controller. It’ll make setting up a CO2 dosing system (for macroalgae) a breeze if I go that route, although I don’t see myself doing that quite yet. The reason is the Ph is at 7.8-7.9. I have never been the type of person to arbitrarily chase numbers (I usually have only a tenuous grasp on what the tank numbers even are at any particular moment), but it seems to me that I wouldn’t want to risk going lower. If I saw the tank was stabilizing at 8.0 or 8.1 or so, I’d happy set up CO2 dosing to maintain 7.8, but if its that low just off the bat, I’m nervous about dosing C02.
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I’m curious why you’d target 7.8 pH? Saltwater should be pretty much equilibrated (as far as O2/CO2 levels) around pH 8.3, if I understand what I’ve read from Randy Farley-Holmes’ articles. I wouldn’t touch a CO2 canister unless pH is regularly above 8.4 but my guess is your sandbed will help keep pH low since it will host lots of decaying detritus.
 
JVU said:
I agree the plastic balls are of questionable value, and probably a waste of space. Being totally honest, I never really understood why people used them, even back when they were popular. I get that they are surface area for bacteria, but you already have a lot, and any porous rock like we use for reefs or those MarinePure balls you have will have 1000’s-fold more surface area per volume. Each one of those MP balls probably contributes more than all the plastic balls combined. I’d just remove the plastic balls personally.
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My understanding is the plastic balls are designed to distribute water evenly in a wet-dry filter setup, and resist clogging. Beyond that I’m not sure where they’re super useful - I guess you could float them in your sump if you’re trying to reduce evaporation.
 
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