Hi there
I would say E IMo the most important aspect about the 1st Marine Tank is Reading & Patience
A 22g is fine as a 1st Salt tank.
IMO I would only use the External for Carbon & Anti Phos, no biological filtration at all
The Bio-Filtration would be taken care of using Live Rock (Around 15kg should be enought).
Live rock is parts of the reef that during hurricans/storms etc. are broken off and lay in the sea bed and become colonised by micro bacteria, copeopds, Amphipods and larger life, the bacteria being microscopic hids itself deep into the very poruse lumps of rock.
This is now termed 'Live Rock'
It is then sold on and is the best, easiest way of Bio-Filtration in a marine tank (**No maintenece needed), when it is introduced to an Aquarium, the life that has either died back or hidden will spring back to life in the following weeks, Mainly the bacertia which is deep in the rock, but it is common to find corals, Algea, muchies,
Feather Ducters.
** The only concideration yo uneed to give to Live Rock after it is in the tank is FLOW, you must have a a continues & good flow over, uder (etc.) or the colonising bacteria will simply die, for your tank I recommend a Flow of no less than 20x, peeps have noticed I personally go for a higher flow than other, (mine is almost 40x) you also do not want any dead spots on the live rock (ie no flow over), I also use Spray Bars, Rotators & also have mod'ed my powerheads to give and open flow instead of a direct flow.
The Bacteria that colonise this rock are both aerobic and anaerobic and there only job in life is to control the levels of nitrites and nitrates.
The reason I say not to use the external is that the media in there once live can quickly dump Nitrates into the tank wheras this will not happen with LR.
And as Nav said in another post you will have to have some sort of decor, so why not get the best and go for Live Rock
As for other equipemnt
Lighting:
Really depends on what you are thinking of keeping in the coral dept., if you are going for softies (Really Nice & Easy to keep) then either T8 or T% Under the Hood or Luminare would do the job
Powerheads:
I would suggest 3 powerheads with enought flow (Overall) to circulate your water about 20x the total tank volume
Skimmer:
IMO one of the most important pieces of equipment you can buy, if you are in the UK I would suggest a Deltec MCE600 as this is a fantastic skimmer.
Now the Fun Part, The Fish:
I would say you could go for quite a few different type of fish, obviously nothing to big, have a look on Live Aquria's Nano fish, see what you like.
Also I would not even concider a Nem for that tank EVER as they are extermally difficult to look after
And lastly Only use RO Water, never tap water, to much nasties in it
Del
