labatt, Waterkeeper is referring to the concept of using live rock for your ammonia and nitrite breakdown. This is a concept you should research, and it is the only way that people with reef tanks would do it. You will learn a lot as you get farther into the hobby, and will probably change out the bio balls at some point. There is nothing wrong with what you have and is what most new aquarists start out with, and what virtually every store would set you up with. It looks like you have a nice unit for starting out, but I'm glad you have a 75 gallon tank. The unit I see in the picture and the sizes you listed will be fine for your tank, but it is considerably small for a 150 gallon tank. Some of these ratings are misleading, this one in particular. But again, it is plenty for your tank, and looks well thought out.
I read your post above and wanted to add some advice. Good sand is an important part of the biology of a salt water tank. I would suggest live sand only. It will help your tank to cycle quicker, and better, and be a much better part of your biological components. Avoid the reference to DSB, that is a completely different thing, and it either is or isn't. 4" insn't, so you would be much better served with 2 inches of live sand as opposed to 2" live and 2" sand. If you intend to add jawfish or wrasses that sleep in the sand you should consider 3 inches, but other than that 2" is fine.Some might disagree, but my 50 gallon has 1 1/2" and my 230 has 2 1/2". I even have a jawfish and a red Coris wrasse which still do fine.
Live Rock is your friend. Buy good stuff, and as much as you can, a rule of thumb is a pound per gallon. By doing this, or going to 90 pounds you could get away with removing the bio balls, as long as you add fish slowly, (but that's a topic for another day). Whatever you start with will be fine because you do have the bio balls. As to future rock, you can add as much as you want (don't go extreme and double it overnight though) as long as it is cured and you don't let it sit out of the water long enough to have microorganisms die off. If you can't avoid adding LR that has had some die off, add it slowly, a piece at a time and watch the ammonia. You can never add uncured rock to a tank that has animals in it though.
There are two schools on glass tops, and a wide ugly line between them. My 230 has glass because I have some jumpers (helfrich firefish, jawfish, ), and the lights are screwed to the underside of the top of the canopy. Glass tops and lots of light will probably require a chiller due to the heat and closed in tank. You can see a picture in my gallery. My 50 gallon has half glass. The reason is that I have a wood canopy which will not allow the use of the light legs. I took the hinged doors off the lids, so that 4" in the front of the top are open. I did this because I don't have a chiller and the lights create to much heat to leave the glass on. I use 1 1/2" PVC pipe that sits on top of the glass (that's why I'm not completely glassless) the the lights sit on the PVC. This allows air to circulate under the lights and helps keep the tank cooler. Ground your tank if you have a lidless tank because you will get mist droplets of water on your lights from the splash of the filter returns, and you could get shocked by touching a moist light housing. Hope this helps.
....i can only hope that mine might look like that one day. Thanks again.
