The problem there is that if you make a mistake, while getting used to it, you can damage the corals and some could die in the process. That will depend on the species as many say.
Besides, if you really want to spend the money on the GFO instead corals, please go ahead. Do the math and see how much you'll spend a year, instead buying the corals. You would save more than pennies, that's for sure!!
Water changes are a must anyways, part of a good maintenance schedule, not only to export nutrients, as we know...
If you target feed, the organisms will ingest what they need, not the skimmer.
Macro algae isn't the way to go either!! I do not recommend it. Waste of time IMO!
Skimmer is a must in the long run!
GAC isn't a must, but small amounts will polish your water and help with organics, keeping your spectrum fairly constant, besides bulb age. GAC isn't directed to remove phosphates only, like GFO! Different application!
It really comes down to what you want to do and the risk you want to take to learn.
You can have all that running in your system and still find a balance.
Again, read the link and decide for yourself!
Don't forget to read the article too!
Don't let people try to convince you what's the best for your system!
If you're already using it and like it, why change?
Good luck!
:thumbsup:
Grandis.