Sometimes you can thoroughly complete your research to ensure the best possibly compatibility between all of your fish, but you sometimes will just end up with all kinds of problems.  The reason for this is that fish can also have their very own unique and individual personalities.  And just like people, you can find miserable , grumpy, and mean fish that are completely different the average fish of the exact same species.  Although I would think this is a very small percentage, it is still a risk.
This is why I always recommend that you keep a very close eye on your aquarium every time you add a new fish to the set-up.  Even when you quarantine a new fish for 4 or 5 weeks, you may still not know with 100% certainty how well this will work out until you add them.

The below link and also offer a few guidelines to help you think through determining appropriate stocking for your aquarium
https://www.reefaquarium.com/2013/responsible-fish-keeping/

The below link can also offer you some good ideas about stocking butterflys in reef set-ups

http://reefbuilders.com/2013/10/29/keeping-butterflyfish-reefs-avoid/

Your salinity level is among one of the more important parameters in a marine aquarium. Maintaining a proper salinity level will help you establish a proper pH as well as making your alkalinity and calcium levels a lot easier to maintain stable.
So what is the proper salinity level ? Many people have many different opinions about this ranging from 1.020 to 1.029 and they will also have a thought process in support of their options mostly around the type of setup they have. As the more popular fish and corals that we keep in the hobby come from in or near the ocean’s coral reefs with a salinity of around 1.026, I prefer to keep the salinity levels my FOWLR and Reef aquariums at the same level as these areas of the ocean, 1.026 (35ppt).  However, there are some exceptions to that.  The Red Sea for example will have a salinity level of around 1.028 to 1.030 depending on the exact location making it better to have a slightly higher salinity level if keeping fish or corals from the Red Sea.

You really do need to understand the water parameters in the area of the ocean that your fish and corals come from before you develop your own approach to maintaining your salinity.

The below link is to a very handy article that contains instruction for very different types of marine test kits

http://successfulreefkeeping.com/resource/aquarium-test-kit-instructions/

Don’t underestimate the importance of waterchanges!

In may low demanding and more basic set-ups, weekly water changes in the range of 5% to 20% would be all that you would need to replace the consumed elements from your water as well as helping to control excesses nutrient build-up. Many people do not realize that water changes when cycling your tank can also be very important and beneficial with harming or prolonging most commonly used cycling processes.

Waterchanges when cycling a marine aquarium with at least some live rock my actually help you out down the road. This is very different from a typical fishless cycle in a freshwater aquarium. Within the nitrogen cycle that develops in your marine aquarium, you will develop bacteria that eats the proteins and turns them into ammonia.  This type of bacteria will reproduce a lot faster than the ammonia eating bacteria, so the ammonia produced can actually grow to toxic enough levels that will prolong the cycle. Typically this point occurs somewhere around 1 to 2 ppm of ammonia. This is why you have to do water changes if the ammonia reaches levels of 1 to 2 ppm or higher. The water change will help reduce the ammonia and other decaying particles from the tank helping the cycle complete faster and the water parameters become balanced quicker. Although there is some beneficial bacteria free floating in the water, it will be in such small amounts that water changes will not remove enough of them to be impactful in any way. This is why water changes when cycling with at least some live rock will help the cycle move along faster, not slow it down one bit.  This will also help to limit the potential for higher levels of nitrates before the nitrate eating bacteria has a change to develop which will reduce the risk of nitrate build up within your rock.

And the below are some more interesting article that I found and thought I would share

http://reefbuilders.com/2013/09/04/reef-octopus-nwb-sss-super-space-saver-brings-performance-smaller-package/

http://reefbuilders.com/2013/08/30/mini-flipper-algae-cleaner-brings-magnetic-flipping-action-smaller-tanks/

Beware of forums !!!

While forums are typically a great source of first hand knowledge, they can also be a pain in the backside for two different reasons.

When first starting and setting up your marine aquarium, your experience is limited.  Even when you research more than enough, you still can make a mistake here and their when you are new to the hobby.  Most of the time this is not a bad thing as there will be no permanent harm to your aquarium inhabitants and you will still be enjoying your aquarium in ignorant bliss, just like I had started started out in the hobby. However, if you unknowingly make a mistake to go to a forum to explain your situation and ask for advice, you will likely get a dozen or so people pointing out all of your mistakes.  This can make it real easy to feel bad about yourself and limit your enjoyment you will get from your aquarium.  Just keep in mind that almost all problems you will ever run into, can be corrected by applying a few basic and simple concepts.  This hobby is not a “Black Art”.

Another reason for this warning is some hobbyist who have many decades of experience can forget they are talking to a newer or lessor experience hobbyist at times.  This can make you feel like someone just explained to you how to build a watch when you only asked what time it was.  Don’t get down on yourself when this happens, and it will happen.  It can be easy to feel like you don’t know what you are doing when a fellow hobbyist tries to sum up his/her many many years of experience into a few paragraphs, just do your best to learn from the information.  Once again, stick to the basics doing those well, and most every thing else will fall into place.

Also, I thought I would share the below links as I found them very interesting and I hope you will as well

http://blog.aquanerd.com/2013/05/diablo-dc3500-controllable-pump.html

http://blog.aquanerd.com/2013/08/vertex-aquaristik-sump.html

http://blog.aquanerd.com/2013/09/picture-of-the-week-mccoskers-flasher-wrasse-paracheilinus-mccoskeri.html

When I took survival training while I was in the army, we were always instructed to get enough firewood to last you through the night and to complete this task before sunset.Once you had what you thought was enough firewood, get three times more fire wood that what you have. I have found this same simple principle should be applied to planning and learning about your marine aquariums.Once you think you have read and researched enough, you could stand to research some more (me included).

I have found the best way to accomplish this is by reading books and articles published by credible and experienced hobbyists combined with talking to fellow hobbyist and taking a good look at how they have set-up their aquariums.  Forums and blogs can be very helpful for you fill in the gaps or help you decide between the many options and approaches you are going to become exposed to.   This also is one of the aspects of the hobby that many people enjoy almost as much as they enjoy their aquariums itself.

The below are some articles that I found interesting and I thought I would share them.

http://reefbuilders.com/2013/09/24/bali-aquarich-shows-picasso-galaxylike-tomato-clownfish-pending-permissions/

http://reefbuilders.com/2013/09/09/gobiodon-species-red-sea/

http://reefbuilders.com/2013/09/09/life-spectrum-max-feeding-finicky-fish/