defective, you have much to learn but you are on the right track posting
questions here.
PH's are for water circulation, current, like found in the
ocean. Turns out our tanks do best with this current also. It helps keep
the system vibrant by exporting waste and oxygenating the water. You will
need at least 2
ph in a 55g, each with 300-400gph
IMO.
SW especially needs this as it holds less oxygen than
FW, hence the rule of
FW tanks supporting more fish per gallon.
A 55g
FOWLR will cost you, I figure, about $300-500 to get going. You can
cut a few corners like Home depot Southdown tropical sand ($5 instead of
$50) see here:
http://www.aquariumadvice.com/viewtopic.php?t=22188.
Another cheat is to use dry base rock (calcium carbonate) (50/50) with
LR,
the base rock gets seeded and turns to
LR in time.
LR costs $3-6 lb, base
rock $1-2. To put this into elementary steps, here is what you need to do:
1) clean the tank, rinse well to be sure no detergents or bleach is
present
2) add sand or crushed coral (aragonite sand, not silica)
3) add water (use conditioner such as Prime or use purified R/O)
4) add PHs and heater
5) add salt (this is the only time you will add salt directly to tank,
afterward you mix in a separate container) to around 1.023-1.025
sg
6) add live rock (and a chunk of raw seafood)
7) set temp to 80F and let the tank cycle (2-5 weeks depending on
LR)
8 ) keep reading articles and posts on this forum
9) when ammonia and nitrites = 0 do a large water change then you can
SLOWLY add hardy fish / inverts
11) start looking for a skimmer (don't skimp on this, it removes organic
waste from the water; unlike a filter that just traps some solid waste)
12) start doing regular water changes (every 2 weeks) mixing the salt in a
bucket (I use a 13g tuppeware container) with a
ph or airstone for 24hrs -
freshly mixed saltwater is not good for fish or inverts (chemical
reactions)
WELCOME TO AA! 
