I have aquired a new tank. Now what to do with it!?

[Satsumas]

I finally managed to ask the owner of this disused tank that had sat in her greenhouse for years but I had been aware of this tank for about 2 months.
It's a 20gal (dissapointingly) but it's a tank for free so i can't complain.

If some of you had read my post "Will Ryukin's Destroy all Plant Life" then you'll know that this tank is intended for the Ryukin.

How it all began...
My stepdad bought two Ryukin's and put them in his biorb, not knowing that they were too big for it. One of them died despite a good attempt to save him from swin bladder related problems due to poor maintenance of the Biorb.
The other ryukin is now in a small tank away from the two other new goldfish in the biorb that relentlessly nipped and chased him.
This ryukin is in need of a bigger home and the tank that i have aquired is intended for him.

However. This new tank is 5 inches longer than my current tank and i am wondering if my 3 Yoyo loaches will prefer it in the new tank?
My established tank is also a 20 gal though and the 5 inches is made up for in height and depth.
My loaches will dart around and chase each other but whenever they swim the length of my tank they haven't got much time before they need to change direction.
That is probably a total contradition in the way that my tank is deeper and taller but loaches are bottom dwellers and the height won't matter will it?
If i did transfer some fish from my established tank then the Ryukin may have to go back to one of my LFS. Which is also another option.

I think part of me thinking this is the fact that i would like a new tropical set up and i think the idea of using the tank for that Ryukin is a bit boring.
However the Ryukin needs it so i have to put him in it really. :?

Here is the newly aquired tank...
http://img183.imageshack.us/my.php?image=dsc09790su9.jpg
The tank is full of water as a test for leeks, so far so good and i haven't noticed any. I left it overnight but it was covered in condensation when i checked it 30 mins ago which doesn't help.

Also what sort of filter would be suitable?
I'm looking at all Eheim external filter's at the minute as i hear they are very well made and probably the best out there.
I would like one suitable for a 40-50 gal but all the ones i seem to find on ebay are for 60gal+.
I obviously don't want to spend any more money than necessary and i was wandering if anyone know's of some Eheim models that would do the trick?

TIA

 

[coldmachineUK]

I don't know anything about ryukin, so can't comment on suitable conditions for these.

The tank you've a picture of is actually the same as one of my own tanks! Very old if I remember right (but mine has lasted something like 15 years maybe they dont make 'em like they used to lol).
I can say I would think a 20G is acceptable for a trio of yoyo loaches. They are a smaller botia species, though at the same time they are also one of the more...character-filled
They need a hiding space each AND some. I.e. provide a minimum of one cave/log for each, and then add a couple more. You should also plant up if you can: again it will relax them some. Decor breaks up the aquascape and gives them something to look at and move around. They're probably very bored!

In terms of filtration: I run Tetratec canisters on a couple of small tanks like this, where I feel I need extra filtration. But, I would think you would be ok with a couple of decent internal power filters tbh. I would go with an Eheim Aquaball (one of the top models, with at least 3 filter baskets for added media such as carbon/floss/eheim stuff). The good thing about these Eheim internals is that they accept Eheim external filter media believe it or not, so you get the best of both worlds. I would use an Eheim aquaball for mechanical filtration (floss/carbon etc) and another internal power filter for biological filtration (filter sponges).

 

[Satsumas]

In my established 20 gal tank my 3 yoyo's seem to be very happy. I have a lot of plants in there with driftwood and slate caves for them to hide in.
I was just thinking a 20 gal long tank would probably be preffered to my more square 20 gal which the trio are in at the moment.

Yeah the tank is very old, it was left in a greenhouse for god knows how long and i assume it was the home owners sons. I presume he left it there when he left home which would've been about 15 years ago (If that was what happened)
Should i perhaps do something to presurve the tank a little longer? Like re-seal it incase it dies on me?

I'm quite into external filters to be honest. They do a great job and don't waste any tank space, the cost of an external filter isn't always nice but the job they do makes up for it.
I am looking at Eheim but i am open to most brands as long as the product is good.

I am thinking about taking the Ryukin back, i don't really like the idea of it but this tank will be going in my room and i would prefer a tropical freshwater tank rather than a tank with 2 ryukins.