tanks require constant attention. With a small volume of water they can easily foul and kill everything in the tank. I understand the budget issue all to well! You will need to do regular PWCs after you have cycled your tank to keep things balanced. Many of us that have small tanks ( I have a 5 gallon nano) also have larger tanks that can supplement their filtration. If you have an LFS
near by that sells RO
water I would suggest using that as apposed to tap or distilled!
Scott is talking about adding a PH to the bucket that you mix your SW
in to raise the temp and make sure the salt is mixed well. When you mix SW
you should let it mix for at least 24 hours before using it in your tank.
The filter you have selected is going to need to be cleaned weekly. You will need to change the carbon weekly as part of your cleaning. The more LR
you put in the tank the better your filtration is going to be.
Get all of those test kits mentioned above as you are going to need to monitor your water closely because of the small size.
Starting out with a small tank can be a challenge but it can be done assuming you are willing to put the time in it.