Fiddler/Red Clawed Crab Environment

[fishb0ne]

Alright, as a continuation from this topic [as the conversation has diverted so much, I decided to open a new one with a new focus], I have decided to set up an environment for my red clawed crab.
I'll describe the setup, suggestions are more than welcome. Then I'll go into some questions I have
Set-up:
-10 gallon tank, the standard $12 stuff from PetCo, with a cover
-Tetra Whisper biofilter for up to 10 gallon tanks
-rocks and gravel
-some plastic decor plants
-7.5w heater, burried
-Tetra instant ocean marine salt
-12" Hydrometer

I know, heater is wimpy but it should handle 5-6 gallons well. Ambient temp in my home in the lows gets to 68 but is usually 70 or 72. My 5 gallon tank has the same heater and it keeps it at a constant 72. The new set up will at the same temps. I am using this heater because basically it's an extra that's been sitting in a box.
Before using the rocks and gravel, I will rinse them with hot water. They are coming from a 75g freshwater aquarium that has been dry for a year now. The tank I will set it up in such a way that the crab can climb top for air and have plenty of places to hide. I know it would be ideal to give him sand, but I like gravel better for several reasons.
From what I understand, red clawed crabs live in brackishwater of a gravity of 1.005 and PH around 7 or 8? The plan is to achieve that, suggestions are welcome as I do not know how to start. I've never dealt with anything but freshwater. Basically I was going to add te water into a bucket and just add salt and mix until I reach that specific gravity, using the hydro for measuring. I plan on having the tank filled only half-way or a little bit more, so we're talkingabout 5-6 gallons.
Am I on the right track? Am I missing anything or doing anything wrong? I'm not sure what I will feed him for starters, I was just going to drop him some of my betta pellets and some dried bloodworms and maybe a pea here and there and some shrimp meat [basically cocktail shrimp]?

Questions:
-How much and how often should I run the filter. Is 4 hours a day OK? More? Less?
-I have some Pimafix antifungal,should I treat the set-up for a day before I drop the crab? Should I also treat the tank maybe once a month with a low dose just as a precaution? Is it OK if I've been doing this in the betta tank?
-In this tank, would I be able to house maybe 2 female crabs? How about 1 female and 1 male?
-Do red clawed crabs and fiddler crabs come from the same environment? Can I drop a fiddler crab too?
-Taking into account that the red clawed crab has been living in freshwater with the betta for a week now, to which I added 1 tbsp of aquarium salt to the 5 gallons, how should I handle the tranzition to brackish water?

That's it for starters.

 

[JDogg]

Questions:
-How much and how often should I run the filter. Is 4 hours a day OK? More? Less?

why not run the filter 24/7?

-I have some Pimafix antifungal,should I treat the set-up for a day before I drop the crab? Should I also treat the tank maybe once a month with a low dose just as a precaution? Is it OK if I've been doing this in the betta tank?

why are you doing this? what if you create strain of super-fungi that is imune to primafix?

-In this tank, would I be able to house maybe 2 female crabs? How about 1 female and 1 male?[/quote i would go with 2f/1m

-Do red clawed crabs and fiddler crabs come from the same environment? Can I drop a fiddler crab too?
-Taking into account that the red clawed crab has been living in freshwater with the betta for a week now, to which I added 1 tbsp of aquarium salt to the 5 gallons, how should I handle the tranzition to brackish water?

That's it for starters.

 

[fishb0ne]

Thanks for the replies JDogg.
So far I've only done one Primafix treatment, I guess I never thought of the immunity issue. The reason I've done this is because I've read other owners doing the same and this coming from reputable sites such as Bettatalk.com. I guess you're right, I'm not a pill popper myself either and I only go for the headache medicine if I really have to, so I will stop the treatment unless I come across other overwhelming reasons to do so.
But do you think it's worth treating the new tank for a day or two, or is it basically a waste? I'm thinking it's a waste, since the rocks and gravel have been dry for a year now, hot water rinse should do the trick. In the picture, do they look adequate?

The reason I do not run the filter 24/7 is, well, basically if I don't have to, I will not. This way it will put less wear and tear on the pump and will require less filter changes. Speaking of which, if run 4 hours a day or so, how often should I look into changing the filters?
I await responses to my other questions. Thanks guys!

 

[theotheragentm]

With filters, you want to change the media once a month regardless of how often you are running it. I know the filter you are talking about and it should prime itself with the water that's left in the container, but these impellers are so small on these motors that it shouldn't be an issue anyway. I'm not sure if these are workhorses like the AquaClear filters are, but the filter should run for quite a long time, even if it's 24/7.

 

[fishb0ne]

Alright gang, the new tank is set up except for the water and the crab. I want to move her asap because I don't know how long she'll take the freshwater environment for. For how she seems to be fine, she eats and everything.

How should I handle the tranzition as to not shock and potentially kill the crab. She's going from freshwater with 1 tbsp of aquarium salt to 5 gal to brackish of 1.008. I'm asuming I can't just dump her in?


From the picture in my original post, can you identify the gravel I am using? It came with the 75 gallon tank my dad bought from a friend, this stuff on the market goes for $1200-1500 stand included and he got it for $300. Reason I ask is because I'm a bit nervous about it for some reason. I know it's aquarium stuff but I've never had gravel that had such a strong ... rock smell when damp. It almost smells like cement. I filled the new tank with water halfway and cleaned the gravel about 7 or 8 times until the water was no longer dirty [dark gray], but I did notice that the tank walls are stained with white spots, kinda like it would if it were really hard water.

 

[fishb0ne]

Today is the second day the crab has been in his new environment. Water gravity is at 1.007 and temp is at a steady 78*F thanks to a great Tetra heater. Question is ... the crab barely moves at all. I find him in the morning almost in the same spot as the night before. I dropped some small fish pellets and I fear he's not eating. I dropped a pea right in front of him but he's not moving. I know these guys can be territorial. Could it be that he's just getting used to the new set-up?
If I go out and buy some sinking food, such as pellets for bottom feeders, can it sit there overnight without creating ammonia problems? I plan on dropping one at night and picking it up the following morning if not eaten.

 

[fishb0ne]

Guys, a little help please. I fear my little guy [well, girl] is suffering and I don't know what I should do. It's been 3 days and she's barely moved. By this time she found a spot to hide in my betta tank and acted a lot more lively. I tried to make her a good home and now I'm affraid I'm killing her.
To recap the info:
Gravity is at 1.007
Temp is at 78*F
4 gallons of water
Tetra Whisper filter running nonstop of course
Water quality should be fine, I barely dropped any food. I have a test kit on the way, alas for freshwater but it should give me an idea of what I am looking at. Again, I'm pretty confident water quality is not the issue.

What should I do? What should I look for? I was going to just let her there and hope for the best but I'm really growing desperate here. I plan on going home for lunch and replacing 1 gal water with 1 gal freshwater to bring the salinity down a bit to maybe 1.005

She doesn't move around unless I poke her. Even then she'll only just get out of the way. I have not seen her eat either. She seemed much happier in my betta tank. I started setting up this new home of hers because everyone I've talked to was stressing that sesarma bidens fare better in brackish. I'm starting to doubt that now and wondering if maybe the LFS guy was right about selling them as freshwater.

I spent an entire week almost digging Google for info on these guys but all I can come across are articles I've already read.

 

[fishb0ne]

Crabby is doing fine, although the tank is still cycling >_<. Ammonia is 0 but nitrItes even after a 25% water change were at .5
I will do another water change tonight and I will add [more] plants.

I want to add a piece of driftwood in the tank but I can't get myself to spend 10 or more dollars for one. I have a piece of driftwood that came with a 75g and has been used for at least one year in it, freshwater.
Pic:
http://img78.imageshack.us/img78/7826/driftwoodel6.jpg
I was told that I should not use that piece in brackish as it may rot or otherwise cause water problems. It hasn't caused any problems in the fresh aquarium, no molding, no decay whatsoever. Can I really not use it at all? If not, what should I look for then?

 

[RoK]

I believe crabs need access to land.

 

[7Enigma]

fishb0ne,

I don't know how I missed this thread but I'll chime in. I see quite a bit of incorrect advice being given to you and even though much of it is late, I think its worth clearing up.

Your filter inserts should NOT BE CHANGED. I don't care what the directions say, they want your money. Everytime you change the filter insert out you take with it all your bacteria that prevent the ammonia and nitrIte from becoming problematic. If it gets clogged just rinse it in a small bucket of used tank water and put it back in. That's it. I've had my tank running for over a year and have yet to replace any parts of the filter. I just clean them every couple weeks in tank water.

PFS is excellent for crabs. It's very cheap at a pool supply shop (50lb bags for ~$10), its much heavier than play sand so it settles out very quickly, and looks just like an ocean bottom. It's very easy to maintain too, since you can just suck up whatever you want and not have to worry about losing a little bit because its so cheap. I use it in all of my tanks.

Don't dose chemicals (especially antibiotics or antifungals) without a good reason. And definitely don't do it haphazardly. A little bit here and a little bit there is EXACTLY how a resistent strain develops. There's a very good reason why when we take antibiotics we are on it for the full course of the medicine, even if we are much healthier by the second day. You need to keep taking the medicine to prevent any damaged but living "bad thing" from sticking around long enough to develop resistance/immunity.

When transitioning any living critter from one condition to the next it always should be done slowly. That means in your case your new tank should have had EXACTLY the same specific gravity as the betta tank. Then you can start slowly adding in more salt to get to the desired level. What happened most likely (and why the crab seemed lifeless for a bit) was you probably dehydrated the little guy. When the surrounding water suddenly gets much more "salty", there will be an outflow of water from the crab to the surroundings (this is REALLY generalizing). Even worse is if you go the other way around (from brackish to FW). Then you have all this FW rushing into the critter and can cause swelling and other problems. Not pretty.

Filters need to run constantly. The bacteria living in them are aerobes. That means they (like us) need oxygen to survive. When the filter turns off due to a power outtage or breaks the oxygen starts to get used up by the bacteria. When all the oxygen is gone the bacteria begin to die and anaerobic bacteria take over (these prefer no oxygen). This can cause you to have to recycle the tank!

Larger water changes are your friend. If you did a 25% PWC and you're still at 0.5ppm nitrIte that means you had close to 0.70ppm prior to the PWC. With slight inaccuracy you can find out exactly how much nitrIte you'll remove at any given change. Just use this simple formula:

Current level X (% water left) = New tank Level

example: I have a tank with 1.5ppm nitrIte and I want to do a 25% PWC. Here's how I find out how much I'll have left over. So it looks like this:

1.5ppm X (100%-25%) = New tank level

1.5ppm X 0.75 (this is the % in decimal) = New tank level

1.125ppm = New tank level

An easier way is to always do a 50% PWC. Then you just cut the amount in 1/2 for each change. On larger tanks smaller PWC's are obviously easier and more common, but if you only have 6 gallons of water in the tank you can do a 90% PWC in about 5 minutes!

 

[fishb0ne]

Thanks for the advice 7Enigma.
I do have two questions.
What is PFS? If I change the substrate now, what are my chances of having to re-cycle the tank?

You said not to replace the filter but I have the activated carbon type in both tanks. What I've read from most aquarium forums out there they all say pretty much the same thing, they replace these things about once a month.

 

[7Enigma]

Sorry, I thought PFS would come up as a hyperlink, it stands for Pool Filter Sand (any Mods reading this? Can you please add it as a hyperlink when moused over, thanks). It is much coarser than normal play sand, and looks just like beach sand. It is excellent for many different reasons.

If you change it now you do risk a recycle so its probably best to wait until the future to think about rescaping. I don't have experience with crabs so I can't comment, but you did mention they prefer a sand substrate. Your crab might like it better.

AC only works at absorbing ammonia/nitrIte for a short period of time (probably a week or 2). After that it doesn't do much, BUT, it has a very high surface area to volume ratio (similar to those bio-beads you probably read about). What happens as the AC starts to lose its ability to absorb chemicals is beneficial bacteria start to populate the carbon. If you keep up on the PWC's for a couple weeks your previous chemical filter will now turn into a biological filter. You won't see any more mini-cycles, and you don't have to keep paying for new filters.

The companies that make them obviously don't want you to know that because then they would only make money on the initial sale of the filter. Most of these companies don't make much money on the initial purchase, its all the inserts and extra's where they make their profit.

Most people that follow the replacement schedule believe it because:

1. The directions say so.

2. They probably had fish deaths when they didn't stick to the schedule.

If you don't stick with the PWC's until the bacteria have time to multiply to handle all the ammonia being produced, the fish/inverts will suffer. It looks then, like you need to replace the filter on time or risk killing your tank. It just takes a little patience to wait out the cycle with some water changes.

HTH

 

[fishb0ne]

You know, I'm starting a new 5.5g aquarium that will have fish such as cherry barbs and especially shrimp. I think I'll get the sand for that then.

So PFS doesn't cloud the water when vacuumed or disturbed even a bit? That's great! Anything I need to watch out for when I buy it?

 

[7Enigma]

You know, I'm starting a new 5.5g aquarium that will have fish such as cherry barbs and especially shrimp. I think I'll get the sand for that then.

So PFS doesn't cloud the water when vacuumed or disturbed even a bit? That's great! Anything I need to watch out for when I buy it?

Once it is thoroughly cleaned it does not cloud at all. Depending on where you get it and how it was stored it can vary in prep time. I live in PA and bought the PFS last December. There are no pool shops open that time of year and none of the large places carry pool stuff then either (Home Depot, Lowe's, etc.). I finally found a place that really wasn't open and they had a large pallet sitting outside in the snow. It looked to have been there for a LONG time. I spent about an hour cleaning the substrate in a bucket running water through it. I put it in the tank and it STILL clouded horribly. I had to do some PWC's to get rid of it, but now its perfect and my fish/snails love it.

Here's a pic when it was first setup (jeez look how barren that was!):

After a large PWC:

After a day:

Recently (what a difference a year makes!)

HTH and gives you some inspiration! We all started from scratch at some point.

 

[fishb0ne]

That looks awesome, congrats on the beautiful tank.
Here's what another user on another forum stated about sand

the only drawback to pool filter sand (first hand experience) is that it will discolour quite fast, and when it does it does not clean off. Algae will turn it a greenish hugh, and the feces and gunk from the tank will also leech into it. It's designed porous so it does exactly that, traps small things But yes it's cheap and works well, just the nice gleam it has when first introduced fades quickly to a darker shade of whatever

Practicality- thumbs up

Esthetics- thumbs down

Is that really such a prevalent problem? How is your tank now? Am I looking at periodically having to clean/replace the substrate?

This is kinda off-topic, but here goes. I have another brackish set-up in which I plan on replacing the gravel substrate just like in this 5.5 dry which is taking shape just now. The sad news is the crabby I had in that 10g started going through it's moulting process but didn't make it. Poor little thing. So the tank is empty once again and after I properly set it up I plan on getting another crab.
The plan is:
-empty the water in a bucket and keep it
-put all the rocks and the few shells in the bucket with the water
-let the pump run in the bucket so the bacteria colony doesn't starve
-scrub the tank of the thick salt that built up on the sides around the pump
-replace the gravel with the sand
-put everything back together
-add plants
-let it set for a week, test the water and go from there

Again, thanks for all the advice.
Is it true that fiddlers are primarily land critters? I think I'm going with red clawed crabby again or any other species that spends a lot of time underwater, as I only have a fairly limited space above water on a rock.

 

[7Enigma]

That looks awesome, congrats on the beautiful tank.
Here's what another user on another forum stated about sand

the only drawback to pool filter sand (first hand experience) is that it will discolour quite fast, and when it does it does not clean off. Algae will turn it a greenish hugh, and the feces and gunk from the tank will also leech into it. It's designed porous so it does exactly that, traps small things But yes it's cheap and works well, just the nice gleam it has when first introduced fades quickly to a darker shade of whatever

Practicality- thumbs up

Esthetics- thumbs down

Is that really such a prevalent problem? How is your tank now? Am I looking at periodically having to clean/replace the substrate?

This is kinda off-topic, but here goes. I have another brackish set-up in which I plan on replacing the gravel substrate just like in this 5.5 dry which is taking shape just now. The sad news is the crabby I had in that 10g started going through it's moulting process but didn't make it. Poor little thing. So the tank is empty once again and after I properly set it up I plan on getting another crab.
The plan is:
-empty the water in a bucket and keep it
-put all the rocks and the few shells in the bucket with the water
-let the pump run in the bucket so the bacteria colony doesn't starve
-scrub the tank of the thick salt that built up on the sides around the pump
-replace the gravel with the sand
-put everything back together
-add plants
-let it set for a week, test the water and go from there

Again, thanks for all the advice.
Is it true that fiddlers are primarily land critters? I think I'm going with red clawed crabby again or any other species that spends a lot of time underwater, as I only have a fairly limited space above water on a rock.

It will discolor to some degree but I actually prefer it. It gives the substrate some character with different shades of color. Unless you actively turn over the substrate (or have MTS) I don't see how crud will get down, it would just lightly rest on top. A diatom filter is excellent for a deep cleaning from time to time as you can blast the sand around and anything lighter than the sand can be removed from the tank. I just did this a month ago on my horrible 10gallon QT/snail tank before getting a gourami. Even with 50% PWC's per week the tank was off the chart with nitrAtes and looked awful. I spent about 3 hours with the diatom literally CLOGGED the diatom filter, did a 50% PWC and everything was good to go.

So I personally like it.

 

[Jchillin]

(any Mods reading this? Can you please add it as a hyperlink when moused over, thanks).

Take a look now.

 

[7Enigma]

Thanks Jchillin.