Bio sphere same function as bio pellet but goof thing is that this no need reactor, just place near the skimmer where highflow water current will do, but it needs work with powerful skimmer for best performance ( this is wat I heard)
I am using salifert and rea sea. For result, both are consider value or money. But in conclusion I will rather recommend salifert due to it simplicity. Especially for NO3 and PO4 test kits, can notice it huge different of simplicity.
As long as your water parameter is keep at right level, with the correct lighting, I believe mostly LPS is not hard to keep right? Anyway I still newbie , heehee
What kind of salt you are using ? Frankly i don't really bottle about the PH but KH, as my reef's friend said as long as your KH between 7-10, your Ph won't swing too much one.
Happy reef !