Glass Aquariums vs. Acrylic Aquariums

Benefits/Downfalls of a Glass tank:
1. cheapest per gallon
2. hard to scratch
3. scratches permanent
4. higher index of refraction
5. empty tank heavy
6. Tank stand only needs to support edges
7. more easily broken

Benefits/downfalls of Acrylic tanks:
1. more expensive per gallon
2. scratches easily (e.g. scraping algae with razor blade)
3. scratches can be buffed out (though not easily)
4. lower IOR (tank distorts less when viewed from angle)
5. same sized tank weighs less (empty)
6.Special stand needed that supports entire base of tank (not just edges)
7. harder to break

Selecting The Right Size Aquarium

Contrary to what you might think, larger tanks are not necessarily more work than smaller ones. For one thing, it is easier to keep water chemistry stable in larger tanks than in smaller ones (the less water, the more easily a small chemical change causes a big change in relative concentration).
Most of the regular maintenance does not require twice the time for twice the size. For example, a regular partial water change for a larger tank may require one more bucket of water than for a small tank. Since you already have the bucket and siphon ready and your hands are already wet, it means just a few extra minutes of time.

Kalkwasser

kalkwasser is literally chalk-water, this is water with calcium hydroxide Ca(OH)2 dissolved in it. Adding kalkwasser is the best way to maintain calcium levels in marine tanks growing corals, clams, and calcareous algae. About 1 teaspoon of Ca(OH)2 powder will dissolve in a gallon of pure water.