There seems to be dirt on my fishtank

[evilhorde]

Good day to you all.
I put together another one of my overly complicated tanks again this weekend and I thought I would share some pics that I took along the way. This is more of an aquarium than a terrarium or a paludarium but I thought I would show it anyway.
First a picture of the nearly final product to pique your interest:

This 40 gallon long tank is basically using a horizontally flowing UGF. The upper deck is watered using an absorbant material I had around here, used as a wick from the tank and hidden behind rocks.
And now into the pictures of what I did. I assume if you are still scrolling you are still interested.
First up: the plumbing.

The pump outputs directly into the opening that is blocked with a black cork in the pic. The other opening will get an airline and stone attached. The idea behind putting air in where I do is perhaps the result of some wishful thinking on my part. When the pump is running the water flow easily moves all of the air down the exhaust tubes and makes a nice bubble wall at the other end. When the pump stops, all of the air rushes through the pump instead of the exhaust tubes, hopefully dislodging whatever has momentarily stopped it. Dare to dream.
Next pic is the same tube nest with the very first layer of substrate, Common black aquarium gravel.

The other tubes in the nest are just there to give a nice solid and even support for the pump box. The box is made of anodized aluminum and has a perforated aluminum sheet for a bottom. On the leftmost side (I'll call it west from now on) there is another screen near the top as a backup in case the bottom should somehow fail me.


Add a store bought ornament to make a nice edge for what will soon be a very deep pile of layered substrates.

The west side of the tank is all lava rock but I have put in sections of aquarium gravel to keep any future shrimp from having any access to the pump box. Under the ornament is a large lava rock chamber for the shrimp to hide in that only they can access and should have good water flow all of the time.

The lid is put on the box and then it is covered in a layer of aquarium gravel (this also is for shrimp proofing the pump box). I have covered all of the lava rock in the tank with a thin layer of gravel because I have noticed that fish like to swim into the lava rocks but they seldom are able to swim back out.

Moving to the east side I have placed an inch or two of sand. I had thought to use soil here but I think that if I move crabs in here they will try to burrow under the stones I will put here later so I kept it sandy there.

Add a little water just for fun.

[evilhorde]

continued...
Add stone, soil and lucky bamboo:
Add more lucky bamboo and another stone to lock it all back along with a bit of gravel to hopefully discourage burrowing in that spot:

In this next picture you can see the place where the sand and gravel meet up under the stones. I suspect there will be some digging here. I hope so. I have tried to encourage burrowing and hiding to be in places of my choosing and I am trying to make places less visible to me into less convenient places for them.

Take a step back and wipe off my brow.

Meanwhile things have been progressing in the west:

Pillars! But what are they for?

This is where I got too excited and forgot to take pictures. I'm surprised I made it this far before I forgot. Oh well. You can imagine can't you? Imagine a sheet of the same perforated aluminum as the bottom of the pump box laying from the west side of the tank on top of those seemingly ornamental pillars all the way to the large glass crossbrace of this tank.

In the sheet I have cut out a 6 inch circle to give the crabs easy access to the water on both ends of the land mass and to make it at least feasible that I could drag a dead body out from under there if I ever had to..

Aerial view of crabland:

A couple of other shots.


All out of pics.
Time for talking.
boring, I know.

The walls surrounding the tank are just plexiglas sheet. All plants are typical local hardware store tropicals. I am hoping that with judicious pruning this tank should be escape proof due to the smooth and tall walls. The wires and hoses exit the rear west side and are buried behind another
piece of perf aluminum sheet which is pinned back with two MASSIVE (to a tiny crab) stones which are also support stones to the land above and buried under more gravel. The 'dry' soil is watered via capillary action
through some 'DACRON' that hangs several inches into the tank. If I haven't made an error along the way, the dacron should be in contact with some lava rock, which should wick water all the way up from the bottom of the tank (theoretically). I wish I had been thinking ahead a little more. I would have run the dacron all the way to the bottom of the tank. I had a limited supply of dacron and I had something slightly different in mind, until I changed my mind again. Too late to cry over that one now. Depending on how easy or difficult cleaning the water line turns out to be, I can run the water level as low as the bottom of the doorway on the coliseum ornament with out affecting the water/air systems or as high as the black trim to hide the line. With a little luck the lavarock/ dacron wick should keep the top well watered.

I wonder what I should populate it with. I have a few danios and neons in another tank. I'll likely move them in and raise their numbers to maybe eight each. That leaves a 2.5 inch bristlenose pleco as the sole inhabitant of a 45 gallon tank across the room. Seems a shame to leave him there alone. Seems a shameful waste of a tank, so I may have to bring it too? Rotten bugger will probably destroy everything, but cleaning algae off of the glass is going to be brutal and since it sits right in front of a window, algae in general is going to be awful. The more I think on this, the more I want it in there regardless of the damage to the decor.
I may need two. :drool:

I can get red claw crabs locally and the internet seems to think that brackish water is not necessary but I think I would prefer to get some truly freshwater species. Ideally geosesarma notophorum 'mandarin crabs'. I have seen them for sale in the US but I haven't found anything up here in Canada. Any tips?

Any thoughts on what I have created?
Have I made some classic terrible mistake somewhere?
Questions?

[x5tr41ghtj4ck3t]

Just a few comments.
I was under the assumption that metals are, no matter how "trustworthy," generally accepted as dangerous to aquarium life. I mean, sure: the impellers in any pump in an aquarium have metal in them and pure aluminum should technically not leach or rust, but it's a metal.... doesn't it react with EVERYTHING?? EDIT: Main concern comes from the amount of surface area the aluminum has. Would the substrate just absorb any ions or compounds that must be a result?

Also, I'm having trouble understanding your escape proof design. I AM in a rush right now, but I would think that any legged creature that could get to that pool on the plexi tank could just climb right up the walls of it, up a plant, and hop over the side. Now, I understand that the likeliness is probably low, especially if the creatures enjoy their environment... but it seems like putting the pool in the center rather than to a side might make more sense. Shrimp can certainly swim up that high, and crabs... well, I don't know much about them...

Actually, I am pretty sure that if a crab is meant for brackish water, it should have it. Freshwater species is ideal and safest. EDIT: Plecos aren't the only thing that can eat algae. How might an aquatic snail fare? Specifically, either a japanese pond snail, or a few nerites.

Gotta run right now, looking forward to your response.

[evilhorde]

The pool and land around it will probably the primary place that the crabs stay (assuming I find some). The plants will be trimmed down to maybe 4" below the rim of the plexi with particularily stout plants getting trimmed a little bit lower still. I had this plexi shield on a different tank and it kept the crabs in. This tank has a lot more land and a lot different plant scheme but I think that with good pruning it should be okay. If they seem to be eager to escape, I can easily add a plexi lid.

I have a real bad case of 'snerpes' here already, any tank I have is quickly infested but in the old crab tank I have none. If I do stock this tank with crabs, I plan on using it as a dumping ground for all the pond snails I scoop out of other tanks. I think I will still need a more serious algae eater though.

---------- Post added at 09:06 PM ---------- Previous post was at 09:02 PM ----------

Almost forgot, the german forums seem to feel that the brackish water is only necesary for an early stage of development for the pre-crab babies. The geosesarma species have eggs that hatch directly into tiny crabs with no larval stage at all.

So, according to the european collectors, the salt isn't necessary for the health of the brackish crab. However, I am with you and I would prefer to find a proper freshwater breed.

[x5tr41ghtj4ck3t]

Is it bad that I did a google search (fruitless effort) to figure out what snerpes meant? After rereading your post, I'm thinking I finally got it... snail herpes, haha.. You're probably right; it all sounds like a good plan!
Would something like this need water changes? If so, how much of a hassle might that be for ya?

[evilhorde]

Originally Posted by x5tr41ghtj4ck3t

I finally got it... snail herpes, haha..

You got it.
Water changes are easy. I just hang a hose over the top. I don't think I have enough plants to go water change free.

I am such a hypocrite. I was just at petsmart, saw the cute little red claw crabs, lost control of myself and bought six.