questions about marine aquariums

Question
Hello there Jennifer,
I have several questions so please bear with me.
Im setting up a 90 gal reef aquarium and Ive got it running, cycled and
everything,  sand, 432 watt light, filter, skimmer, power-heads, heater Ext.
Ive also got 2 O clowns  and 135 lbs of Live Rock.Here are my Questions:

1st. Macro-Algae...I was thinking of getting some for the display tank, say: 2
red grape kelp's and 5 shaving brush's. Would they remove a considerable
amount of phosphates/nitrates? How much would you guess? 5 ppm a week?

2nd: I plan on Getting a bubble tip anemone for my clowns. Do you know any
ways i can get them to host? i do not want to get an anemone just so my
clowns can decide the want to host in a frog-spawn instead.

3rd: Stocking. After acclimating my clowns i shockingly have no want to get
anymore fish! Sure another fire-fish or Gobie would look cool but what if i
just didn't add anymore fish? It would be better for the corals, anemone and
maybe even the clowns. What do you think? Would getting a pair of Neon
Gobies and a pair of fire-fish make that much of a difference or would having
a 90 gal reef with just a pair of clowns be better?

Thank-you for taking the time to answer my question.
Austin,

Answer
Hi Austin. For your first question pertaining to the macro algae; it is all going to depend on how much you are going to put in your tank. If you are only going to introduce a little at first you will probably not notice any difference in the amount of phosphate or nitrate you have in your tank. As it grows it will take up more of these and then you may see a difference. However, if your nitrates and phosphates slowly creep up as the macro algae uses it up you may still not see all that much of a difference. It is really hard to say exactly what kind of a drop you may see in these two tests. Typically you need a lot of macro algae to actually see all that much of a difference. Also phosphate and nitrate will ultimately go up as the biological processes go on in your tank and the algae may only keep them from getting higher not reduce them.
The clownfish you have may or may not take to a bubble tip anemone.  Most likely they will and the best way to ensure that they do is to introduce the anemone and wait and see! If you are concerned about the clownfish favoring something else like a coral, then introduce the anemone first and give the clowns a little time to take to it and form a territory around it. Once settled in to an anemone clownfish will rarely leave it and will almost never take to something else in your tank with the exception of another anemone.
As for your third question; It is all up to you! Having a reef tank is more of a habitat for the corals. Fish are usually an after thought to accent the corals or give the tank a bit more life. If you are perfectly happy with having just the two clownfish in there then do just that! Corals can be very sensitive to fish waste and too many fish will actually make it harder to keep the corals. Less fish is always best in a reef tank.