Setting Up And Stock Levels

[simonmealing01]

Hi all I am new to keeping fish so we have got a 125l tank with a external filter its 2nd so we want to give it a very good clean then new black sand new plants and new ornaments we will also be putting new filter media in as well then let to run for 4weeks to get it going before the new fish go in


My questions are
What would be best to give the tank a good clean before I put the new sand and plants in

What would you say is the best way to do a fishless cycle

Then the big question stocking levels and what fish
We would like some
6x bleeding harts tetras
6x Columbian tetras
3x black Molly's
Not sure what else as not sure what the tank can hold

The other thing we like the thought of is some red claw crabs with a floating platform and some rocks to climb up and a cave or two to hide in

I would be grateful for any help
Thanks simon

 

[Munroco]

Is the existing filter media dried out? If not would be better to keep it as it may have some bacteria still living in it which will kick start your tank.
 
Would not recommend mixing mollies and tetras, mollies benefit from harder water and many fishkeepers will add salt for mollies. Tetras normally prefer water with a lower PH

 

[simonmealing01]

The filter should be wet as the tank is only going to be empty end to day and I am picking the tank up tomorrow so should be wet

I will keep that in mind about the mollies

But if I swapped the mollies for a different fish of the same size how would my sticking levels be and would I have room to add more over time

 

[the_lock_man]

I would echo the thought about the mollies, whilst they are sold as freshwater fish, everything I have seen and read indicates that they require slightly salty (brackish) water.
 
With your two tetra species, your tank is crying out for apistogrammas, IMHO. A male as a centerpiece fish and 2 or 3 females of an apisto species, my personal favourite are Agassizii, but also wonderful fish are Cacatuoides (Cockatoo Cichlid), Hongsloi (Red Stripe Cichlid), Macmasteri, Nijsseni, Borelli - depends on what your LFSs have in stock.
 
With regards to other fish, I think you'd be better off increasing the numbers of the BHTs and Columbians - it really is a case of the more the merrier with these species. One of my local stores has a 1200litre display tank with around 300 Cardinal Tetra - simply stunning.
 
If you can keep to South American plants as well, you'll have a lovely SA biotope tank to be proud of.

 

[Byron]

I agree with the other members on the mollies and tetra, more on the latter momentarily.  To your initial question on cleaning; I assume this is a "used" tank, so I would use hot (not boiling, just hot) water to clean the tank glass and filter housing.  Some might suggest bleach or perhaps vinegar, on the off chance of killing pathogens, but make sure you thoroughly rinse the tank/filter several times with tap water if you do, and allow to dry completely in the air.  I would myself stay with very hot tap water.  Do not use any of the filter media or the existing substrate, which I gather is what you plan, as getting rid of pathogens in either of these is next to impossible.  And you certainly do not want whatever may have lived in these previously, good or bad, so you are very wise to replace them.
 
Knowing your water parameters (meaning the hardness or GH, and pH) for your source water (tap or well) will help us suggest fish.  While some are adaptable, to some extent anyway, some are not.  Mollies have already been correctly identified as requiring harder water or they will not last long.
 
Aside from the parameters, tetra are characins and the larger the group the better.  But here we come to some issues with the species mentioned.  Both of these are on the large side by comparison, and both may have a tendency to fin nip sedate fish, so think through first.  Possibly-nippy fish tend to be more inclined to do this in fewer numbers.  The other thing is the tank size; 126 litres is 33 gallons, and this is not a lot of space to the fish.  I will assume a 3-foot length maximum.  Bleeding Hearts attain 3 inches, with 3.5 not unusual; Colombian Tetra attain 7cm or 2.5 inches.  I would not have both in this small a tank.  A group of 8-9 Colombian, with substrate fish, and/or the dwarf cichlids another member mentioned, is one option.  Or go with the Bleeding Hearts in a group of 7-8, plus substrate fish, etc.  All these fish are very small in stores, and I know it is sometimes difficult to imagine such a "small" group of them ever filling a tank, but they will assuming they are healthy and have a good environment.
 
Byron.