Natural marine set-up

[Caryl]

One of our favourite tanks we set up was a rock pool marine. We got a 3ft tank then headed out to the Kaikoura coast (without the tank - we took big plastic containers).

We loaded up with algae covered rocks, sea lettuce for food, and collected pool critters and sea water. Back home we arranged the rocks in the tank (I think we used an external AquaClear for a filter), poured the sea water in then added the critters.

We had a number of triplefins (salt water cockabullies) a little rock cod, lots of shrimps, anemones, chitons, a hermit crab, a sea cucumber and (don't tell anyone as I believe they were illegal) a little paua and a crayfish. All were picked up in the rock pools.

At one stage we even had a little octopus but he escaped one night and was fluffed to death on the carpet.

It was a fascinating tank to watch. Shrimp don't look too interesting in a pool but seen side on in a tank you can see they have red knees (and more than two of them!). The patterns in the fish were amazing too.

On weekends we would head to Whites Bay and get more sea lettuce and sea water. We figured there would be lots of little microscopic stuff in the water for our critters to eat. Apart from that we rarely fed them.

Our biggest problem with it was the heat in summer. The tank needed to be about 10 degrees C and no higher than 15 but our room averaged 28 degrees all summer, never dropping below about 22. I would like to set a tank up again but with a proper cooling unit. I have a tank - just no-where to put it!

You are allowed to go dive and catch fish but I would not do so because the fish in the sea are used to swimming in large areas and grow too big.

[Pegasus]

Hi Caryl, Ira,

Now THAT is a good post he he.

Just shows, it can be done.

As pointed out Ira, it's not the couple of cheap fish that is the prob, it's keeping them alive in the correct enviroment, and Caryl here has explained an alternative that many of us could try if we want to venture into the cold water marine world.

Good post Caryl... Great reading.

And yes... you did put it in the right place

Bill.

[Ira]

Keeping them could would be a LOT harder than keeping a tropical marine setup warm. Which doesn't make things easy. Sounds like fun though, Caryl.

Actually, I've been putting way too much time into thinking about how to keep a tank cool, for some reason. One interesting but expensive way I've come up with is bunch of peltiers cooling a piece of aluminum that the water zig zags back and forth through with the peltiers pumping the heat into a really big heatsink with fans on it. Would be expensive though. Searching through the forum, Warren said he could get 50 watt peltiers for about $35 each. I think to keep a tank at 10C in the middle of the summer it'd take at least 300-450 watts of heat removal and probably need about 600 watts worth of peltiers. So that comes out to $420 just for the peltiers, add maybe $300 more for heatsink, fans, getting the aluminum block made up...Expensive. But you could always flip the polarity around and use it as a heater. Or use a watercooled heatsink and put the heat into keeping another tank warm...I need to quit thinking so much at work.

[Pegasus]

Hi again,

You say,

Keeping them could would be a LOT harder than keeping a tropical marine setup warm

Not in full agreement with you here, but it would certainly be a LOT cheaper if you had any fatailities.

BTW. I have several large heatsinks in my growing pile of electronic junk if they are use to anyone, plus ancient computers, printers, hard drives, plotters, syzmic (sp) graphs for vibrations, elecrtonic and pulse counters.... errmmm wrong section and topic :oops:

emails only he he.

Bill.

[Ira]

How hard is it to keep a tank warm? Throw in 1-2 $50 if you're cheap heaters, adjust them to the right temp. Done.

(In case you misunderstood because of that typo, I meant keeping them cold would be harder.)

I tried catching some freshwater cockabullies and keeping them in a small tank once. I caught about 8-9 little fry, couldn't catch any adults. Was fun chasing after them with the nets I use for my tanks, but the adults were too fast and my wife thought I was an idiot. Unfortunately they were all dead within 2 days. I think next time I'll try putting in a heater with the temp as low as it will go and a small filter and not trying dropping a tiny bit of a couple different types of food in the tank to see if there was anything that they'd eat.

[Pegasus]

:oops: :oops: :oops: :oops: :oops: :oops:

Shut up Bill.. You've said enough.

[dennis]

Ira i keeped 4 cockabullies in my turtle tank for about 3 mouths

then they were gone and i did not feed them any thing just the turtes food

[Caryl]

We were keeping the tank cool by freezing 2 litre juice containers filled with water then floating them in the tank. The poor old freezer was running non stop trying to freeze them as we needed 15 of them (both 2 and 3 litre) to rotate enough to keep the temp down. We now have an air conditioner in the room so perhaps keeping the temp down would not be such a problem next time.

[Ira]

Did you consider letting it warm up to room temperature? I don't know if the animals in there could handle it or not, but I'd be inclined to think most could. However...Probably would have been good to try testing it on a smaller scale than the whole tank. Don't want to lose all that work collecting them if they couldn't handle the heat. Yes, I know, bad fishkeeping and all that, but still, most animals are pretty adaptable and...Well, I'm too lazy to swap 15 bottles of ice a day.

[Caryl]

No they couldn't - that was why we had to keep cooling it. Consider the temperature of sea water (it doesn't warm up much on the Kaikoura coast). The rock pools we collected from certainly warm up in the sun but only for a short period. When the tide comes in it cools down again. They are only designed to cope with heat for the period between tides. Higher temps for days on end kills them very quickly - and boy do they smell! (says she speaking from experience)

[Ira]

I just thought of something, the cafe at the place I work has a big...I don't know quite how to describe it...tray kind of thing that must have a freezer unit under it built into the count They use it to put fruit and meat in dishes to sell during lunch. It's a similar size, maybe a bit bigger, to my 200 liter tank. If you could get one of those that was being tossed out or could buy one it should have more than enough grunt to keep the tank cold if you put the tank on it. At the very least it builds up ice in places that aren't covered. I wouldn't have a clue where to look for something like that though.

[Dr.Felix]

i kept a 3 tank tiered setup for a couple years using cold saltwater. in the summer we used irrigation hose coiled in the fridge (NEATLY sealed around the fridge seal) to keep it real cool on those hot days. nowadays one could easily purchase a plastic radiator from a modern automobile and pump the water through it, fan cools - easy.we didnt even use a protein skimmer (just an airlift in the filter box dumping into a coke bottle - roshambo extreme - 18 year olds budget styles.)

the crabs eventually shifted a big rock through the front pane of the 6foot tank and then it was the 4 foot and 2 foot connected. we ran it like that for a while too until someones parent said hed like to shift house and there wasnt any facility to continue it further. easy setup. anemones and shrimp propagate like wildfire! cheap as chips and no deforestation of tropical coral reefs...just the local rockpools and beach.