In fact I believe that maintaining water quality is easy and you don't have to spend as much time as you think on maintaining it. As long as you've got the correct amount of filtration and you don't overstock then it's a simple job that's not even a chore.
For example, my 6' x 2' x 2' tank holds about 175 gallons of water and as a rule I change 10 to 15 gallons about once every two weeks. This may be less than the books recommend, but my tank is not that heavilly stocked, which is deliberate as I don't want to be changing water all the time. The water I use is only ever RO water as I want to give them the best, I have the unit running pretty much all the time and just swap water containers over when they're full. To mix up salt I add just under 2 pints of salt to a 5 gallon water container and leave it over night with a small powerhead and heater running to mix it up and get the temperature right. The salt levels the next day are almost always at the correct level. If they're not quite right it doesn't really matter as in a big tank this small amount of water doesn't have that much effect on the salt levels in the main tank. This may seem a bit too care free but it really isn't, lets say that my desired salt levels are 1.024. If my water change mix is 1.023. Then when you've changed the water, wait and then test it again you won't even notice the difference, and all you have to do to correct it is to add a little salt to the sump tank if you want to. Besides when you top up for evaporation you change the water chemistry a lot more. I also add Iodine, strontium, molybdenum and a ph buffer to the change water. It seems the easiest way. Again this is easy, one capfull of each trace element and half a teaspoon of ph buffer.
Some people say that they spend an hour a week on maintenance, but if you break it down it's not that long.
Connecting RO unit.................1 minute
Adding salt, trace elements heater and powerhead ...............2 minutes
Syphoning off 5 gallons of water 2 minutes
pouring 5 gallons of change water into tank.............30 seconds
So you can see water changes take only 5 minutes 30 seconds.
If you test for nitrates and ph each week then that only takes 10 minutes, While your nitrate test is developing you can test the ph. Better still when you have a mature tank and you are used to all this water changing and testing you get a feel for it and you won't test so often.
you're probibly wondering where my ammonia and nitrite tests are ? well I don't check them that often as I never get a reading. This is because I have a matured tank. If you are just starting out these tests are important as these chemicals are highly toxic to your fish etc.
Ammonia tests are important indicaters of fish deaths also. If a fish dies behind the rockwork you may not notice that it's gone, But in a small tank especially you could get an ammonia spike, then a nitrite spike and this could spell disaster. But in a well matured tank this is usually not a problem.
My theory behind good water quality is all about live rock and a clean up crew. I thoroughly believe that live rock is the way to go and I can't speak highly enough of my hermit crabs and brittle stars. I have approximatly 40 crabs in there and they clean up all the left over food and if a fish should die then it wouldn't be around for long enough for me to see the evidence.
Water maintenance is the main reason many people choose tropicals over marines, but I have learned through experience that it's not really that much different, It's just a little less forgiving.