You have decided that the marine hobby is for you. You can't wait to
get started. But first buy or borrow a good book or two. This means a modern book, aquarium technology
has developed rapidly in recent years.
When I restarted, I got a huge amount of information from The Modern Coral Reef Aquarium,
Vol. 1 by
Svein A. Fossa, Alf Jacob Nilsen. But this book is really quite old now, and there are more modern books covering the latest, for example, on lighting, where LEDs have taken over.
Read up a bit, so you won't be completely lost when dealers and other enthusiasts talk
technical stuff, you can also more easily switch on your bullshit filter.
Try to go when they aen't too busy. The salesperson/ owner should show you what equipment they recommend, what they have in stock, and what they use in their own display system.
Any dealer worth their salt!? will have a display tank with a working filter in a closed system i.e. NOT connected to the sales tanks. This shows that they can actually talk from experience about a system which will work in the same way as the one they wish to sell to you.
Don't expect a dealer to have all the most modern ideas fresh out of last month's magazine on working display. This isn't the latest HiFi or electronic gadget you are buying and they are, after all, there to sell you a tried and tested system that they know will function longterm.
Look for a dealer who doesn't want to separate you from your money within the first few minutes
Although a dealer may have vast experience in aquarium care, you can't expect them to be a joiner, electrician, plumber or an expert on static floor loads.
You need to have a rough idea of where the aquarium is to be sited, how big it should be, what livestock, in general terms, you want to keep, that means fish only or fish and invertebrates, since most corals need intense light to flourish and are less tolerant of poor water quality.
Generally, the most tried and tested is the 'Berlin' System. This consists of a drilled tank, with an overflow (usually in a corner) which leads the water under gravity to a filter sump, essentially a smaller tank which can be used as a filter, and contain various items of equipment which are then out of sight. The water is then pumped up and returned to the tank. Automatic top up of water can all occur out of sight. The tank water level is regulated by the overflow.
The Jaubert System is simple but effective, uses a deep bed of coral sand over crushed shells. A plinth below this leaves a space between this and the bottom of the aquarium. I have used this succesfully for many years in a small system with corals but very few fishes, shrimp etc. The breakdown of waste is supposed to then produce nitrogen, by reduction of the usual nitrate and some acids which then dissolve the shells and sand, replenishing levels of calcium in the water. The 'Deep Sand Bed' System is fairly similar, apart from having no plinth, which is considered unnecessary. There are. of course, other systems, from 'natural' using little or no extra filtration, to high-tech chemical filtration systems. I leave you to choose, but bear in mind once again that a good dealer will not sell you a system they do not have long experience with.