@AMDPower Thank you for such a detailed response.
I don't own a tank yet, I've kept fresh water fish off and on my whole life and am wanting to do a marine tank if I'm going to do it again at all.
Whether free standing or built in I've only really got space for a 4ft tank and I do intend to automate everything where possible. The cupboard space where I could possibly house my sump etc is a space roughly 2ft deep and 3ft wide which conveniently has electrical sockets already installed.
I am planning on the obligatory corals and clown fish to begin with, if I do it.
no problem
, kept marine for over 10+ years and I will build a 8ft tank next time if I ever get the time.
The hardest part for you right now would be designing the sump, making sure the baffles are correctly sized and correct number of chambers for equipment you want right now or might have in there in the future, 3ft x 2ft will let you get a nice size sump in there. I would either let someone design the Sump and Tank for you, this will save you a big headache, or take your time researching what you are going to be putting there and getting the correct flow rate through it vs the size of the chambers, this is very important. I designed my own sump and learned the hard way even though I did my research but managed to make it work in the end. Its hard to explain with words on a forum.
generally equipment in a sum are
1) Reactor, like calcium reactor, nitrate reactors, phosphate reactors.
2) protein skimmer( A MUST)
3) You top-up system goes in there( this needs it's own chamber ideally)
4) Heating elements and such, some like to have one heating element in the main tank and one in the sump for redundancy
5)cleaning filtration system and such, specially the automatic filter system you see that look like a automated toiler roll dispenser.
6) carbon filter go in there too
You also need to make sure its has enough volume for any backflow that happens when you turn the pumps off to feed. This is water that goes from your main display tank back into the sump, need enough space in the sump to make sure it does not over spill onto your floor.
get yourself some really good live rock, by this I mean rock that has either been taken from the ocean directly or has been seeded in a tank where there is rock that been taken from the ocean, so there is all kinds of little critters and worms that live in it.
you need to decide how deep you want your sand bed to be, look into this and how coarse for fine. There are pros and cons to both so do some research there.
as for corrals as this is your first tank keep mainly LPS corals, personally myself I would stay away from SPS corals right now as you are just starting out. SPS are difficult to look after, require stable water chemistry and high flow and powerful lights to make them grow and pop in colour, keep to mainly LPS as they are easier. I would also not go for big fishes, like tangs or angels, specially the larger species or dragonets, dwarf angels are mostly ok but can nip corrals, unfortunately with 4ft tank you cant keep the larger marine species. The small angels are in my experience been ok, apart from the coral beauty that can nip at corals. Get pair of clowns and some LPS and see how it goes if after few months you doing ok then start adding other stuff slowly.
get yourself onto a forum, something like ReefCentral
its a learning curve but you will love it once its done. I regret closing my tank down but if ever opportunity arises will do it again.