Can anyone lend me some advice. I am starting a new 18 g. reef tank. It has been up for about a week. I have about 20 lbs. of LR in it that I took out of my 55 g. tank. The lighting on the 18g. tank is a coralife 10,000k. The only filtration is a Topfin 20 backfilter, and an undergravel...