Question on how to heat a tank that is half sand half water?

[MalawiManDan]

Ok i'll be setting up a small glass aquarium for a land crab, I need to keep then water to 22-24C which is easy with a aquarium heater, but how do I heat the sand (land) area? It gets cold in the UK lol so the African crab won't like it in winter haha.

My set up will be 3 inches of 1mm coral sand on one side of the tank sloping down to the other side slightly and 3 inches of fresh water on the other side, a bit of bog wood separate the sides to help stop too much sand sliding into the water area, They'll be a few rocks in the water too and a thin layer of 1mm coral sand on the bottom.

There will be a small internal filter in the water to help keep it clean, i'll try to extend its spray bar buy buying and adding on a bit of clear pipe and stick it on the tank with suckers going around to the other side, this pipe will go over to a corner of the aquarium sand on the opposite side of the tank, I'll get the spray bar to go spray over a rock or something on the sand to prevent too much sand being dislodged, I hope this will help the sand area not dry out.

Now with all this in mind, how can I heat the sand area? Heat mat under sand is not possible due to water in the tank. I don't know if I can put a heat mat under a glass aquarium? between the aquarium stand and the glass aquarium bottom? I don't want anything to burn, plus will the heat actually transfer through the sand anyway?

Can't use a heat lamp as that will dry out the sand and crabs then kill them (they need a moist environment, they live on the waters edge, but not in water)

Any suggestions?

 

[Laeris]

I've seen small disc shaped heaters at big box pet stores. Amazon has it as well http://www.amazon.co.uk/gp/aw/d/B00...dor+heater&dpPl=1&dpID=41-6BJ9sW7L&ref=plSrch Honestly, the price it sells for around here would equal 6.70 GBP, I can't fathom why it'd cost so much! Such things exist, though, so you should be able to find it much more reasonably priced.

 

[MalawiManDan]

I've seen small disc shaped heaters at big box pet stores. Amazon has it as well Hydor 15w Slim Heater for Aquariums up to 10 gal:Amazon.co.uket Supplies Honestly, the price it sells for around here would equal 6.70 GBP, I can't fathom why it'd cost so much! Such things exist, though, so you should be able to find it much more reasonably priced.

That's shocking lol, they cant even give you a accurate temp, there is no way to adjust the temp lol, I don't know how the makers sell any of these lol. it just says it heats 5-10C warmer then the room temp, on a random night out on the p*ss after 20 pints I could still be more accurate then that with the mrs hairdrier blowing in the tank haha

 

[ReefGuy77]

It sounds like a reptile heating pad under the fish tank would do the trick for you, but I'm wondering if you would even have to do that. If the sand is partially submerged in the water wouldn't a heater in the water keep everything warm? Is there something I'm missing, maybe I'm misunderstanding what you are trying to keep warm. I kept fiddler crabs a while ago and had built up a slope with sand and the sand remained warm from the heater in the water. I'm from New England so the winters get cold here as well

 

[MalawiManDan]

i have to put bogwood inbetween the sand and water to stop the sand gradually just falling into the water. So the sand wont get heated, i need air temp of around 28c and water temp 22-23c

 

[GreenGo]

If the crabs stay near the waters edge, you may have success with running a small pump and pumping water to a corner of the sand which will flow back towards the water section if you have them connected. If not, I'd go with a reptile heating pad like reefguy said.

Also, I don't know if an under tank heater will heat through the sand, but that was my first recommendation. What you may want to do if none of the above work is test it out to see if it'll transfer through the sand, but this is coming from a scientist in training so I'm kinda into experimentation more than most.

In looking at similar heaters (as you commented on in post #3) for my panther crab breeding project (a type of aquatic crab) I too thought it ridiculous that they couldn't guarantee a more accurate temp, but so is life a guess

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[livefishguy124]

i know that there is a thing as a heating wire or something like that to keep plants roots warm and heat the sand.

 

[Pseudomugil]

I have this little mini heater that's like 3 inches long for my 20 gallon semi aquatic red claw crab tank. It does a great job and it was really cheap. I'll have to check what exactly it is.

 

[MalawiManDan]

I have this little mini heater that's like 3 inches long for my 20 gallon semi aquatic red claw crab tank. It does a great job and it was really cheap. I'll have to check what exactly it is.

does the water heater keep the whole tank warm? or just the water? I already bought a small aquarium water heater, just wasn't sure it would heat more then just the water though, 50% of the tank bottom is water, the other 50% is 1mm coral sand. (Rainbow crab set up)

 

[MalawiManDan]

i know that there is a thing as a heating wire or something like that to keep plants roots warm and heat the sand.

Can't seem to find anything like this in the UK? Can you remember its name?

 

[GreenGo]

It's sometimes called an undergravel heater cable, undergravel cable, or cable heater

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[coralbandit]

IMO if the tank has a lid the air will be the same temp as water and sand.
without some kind of forced exchange?
Also lots of humidity(condensation on glass).
Any heater will not shut off till it reaches temp so IMO any heater should really work(even buried in sand).
Although I can not say they are designed to be buried,which is why I offer link.
Heating Cables for Planted Aquariums | Swell UK Ltd
If the tank does not have lid then the difference in temp desired may still be difficult...

 

[Pseudomugil]

does the water heater keep the whole tank warm? or just the water? I already bought a small aquarium water heater, just wasn't sure it would heat more then just the water though, 50% of the tank bottom is water, the other 50% is 1mm coral sand. (Rainbow crab set up)

It only heats the water but the crabs don't even really seem to care. As long as wherever you're keeping them isn't freezing cold they should be fine. Or another way you can get light and heat throughout the tank is get one of those metal wire top reptile tank lids and put a heating lamp. I did this with my fiddler crabs a few years ago and it did great.

 

[Bpophoto79]

I would think that if you are circulating heated water through the sand it should be fine.

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[GreenGo]

It only heats the water but the crabs don't even really seem to care. As long as wherever you're keeping them isn't freezing cold they should be fine. Or another way you can get light and heat throughout the tank is get one of those metal wire top reptile tank lids and put a heating lamp. I did this with my fiddler crabs a few years ago and it did great.

+1

When I kept panther crabs the first time I kept one in an unheated 10 gal, and the ONLY reason he climbed out was due to it getting below freezing one night (in AZ that's rare). It had gotten close to freezing before, maybe within 5 degrees F, but he didn't try to find a warmer place to live until it actually dipped below freezing.

Of course, it's not something I'd recommend -- keeping them in an unheated tank, especially if you want the fastest growth and to breed them (or am I really the only one?) -- but it's doable to only heat the water portion and they should be fine.

Ideally, though, like the comment above (below the one I quoted) you'd likely be best with flowing warm water through the sand if you're setting it up like that, where the land and water aren't totally separated. Instead of a pump like I mentioned, you may also be able to get away with a simple air stone and pvc method if that interests you more since the prices of pumps aren't cheap.

Let us know how it works out!

P.S. Any method mentioned on this thread should work reasonably well from what I can determine, so you don't necessarily need to aerate the sand with warm water, but that's what I think will work the best with the fewest problems. Thing with cable heaters is they may need replaced eventually which means a total overhaul of the tank, and the same if the cable heater needs maintenance or if any other "simple" issue needs addressed.

The other method that might work better than mine (and more importantly with less stuff in the tank) is the metal wire top with heating lamps, and all you'd need to do is make sure the water is a constant temp with a water heater if you have one. That should provide ample humidity so the crabs don't dry up, though it might be worth it to try the same methodology with a glass top to capture as much humidity as possible since you're going to keep a land crab which won't likely enter the water even if it needs to (unlike fiddler crabs which are semiaquatic and will enter the water to ensure they don't dry themselves out). The glass top can then be vented to allow excess humidity to escape if need be.

~GreenGo, future Aquarium Population Ecologist with an emphasis in Sustainability and a preference for freshwater crabs and shrimps (whether aquatic, land, or semiaquatic, it doesn't matter with the crabs)

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