Oscars + UV Sterilizer?

hello again,

tank- 90g
filtration-fluval 405, AC110 (possibly one more AC110)
2 - Lutino O's (4 1/2 ")
1 - Pleco (4 1/2 ")

this tank will be up, cycled and stocked by the end of Jan early Feb.
my question is do i need a UV sterilizer? or it it an extra precaution more than a nessecity?
basically what are the cons/risks of not having one.

yes ive heard its adequate to overstocked.
getting about 50/50 on that one but i dont believe it will prevent them from living a decent life. ( no stunting etc).so i will conitnue with my plan.
im somewhat of a perfectionist when it comes to cleanliness in general,
so as far as water changes and general maintenence it will be no concern.

ty for your advice on the UV Sterilizer.
i dont mean to sound ignorant or intolerant when i say im going to continue to house them in a 90g, with the reaction/suggestions ive gotten from numerous oscar forums it seems very reasonable from the experienced oscar enthusiast/keepers that 90g is adequate and 2 (be it they tolerate eachother) can live a long/stable life in one.
they are in a 55g growout atm and do get along (when i bought them they paired off from the rest in the tank), but adolescent stage is right around the corner so we will see.

yes it is a common pleco. i might get him adopted out when the time comes because of the size it can get.
once again i have been told few diff things
1 was that he should be ok (although i do think likewise, only if short term)
and 2 i should get a gold nugget instead (which i hear can easily become oscar food due to size).
the pleco i have now, i rescued from a friends grandma a year ago who had him in a 20g with guppies.
hes in the 55g growout with the o's but will eventually contradict my rescue attempt if i can not properly house/maintain it myself.
i do treat my fish like any other pet be it a dog, cat etc. so do want to provide them a good life.
As i stated about the O's i do believe the 90g should be sufficient and will follow through to house them in there. However, if in the future i do find it is inadequate or have territorial issues i will buy another large tank.
unlike some people out there my pets are not my house decorations/guards or trophies, they are my pets, members of my family and i learn, and do what i can to protect them.

yes im leaning towards keeping 4 12" pleco in the 55g till i can find a home for it.
as for water changes its not a prob.doing pwc's every couple days is no hassle to me at all. just like bathing my dog and walking him every day is no inconvenience, it is a nessecity.
i will be carefully monitoring (testing) the water conditions in the 90g as well as carefully monitorin behavior.
like i said before, with no disrespect to anyone, i do believe 2 O's in a 90g will be ok provided the porper water conditions.i do respect everyones opinions equally and appreciate any and all feedback.
however back to my question at hand,
the UV sterilizer, what are the benefits of it in an oscar tank
and what are the cons of not having one in an oscar tank
i am 99% sure i am going to buy one just wanted to make sure it wasnt just some kind of marketing gimmick etc.

sorry Mgamer, where do you get the "dont want to take into a count the options of others why ask?" from?
i obviously do want opinions of others if i am asking lol.
the 99% sure im going to buy one is in relation to the information i have recieved thus far.
IMO, i think your just offended that i dont have the same opinion as you on the 2 oscar in the 90g idea, but that isnt even the quesion i had asked.
im simply asking for feedback on a UV STERILIZER for my oscar tank.
i have already posted about (housing 2 oscars) in numerous forums and have made my mind up, which is why theres no debate for me on that subject.

once again................
what are the benefits of using a UV sterilizer in an oscar tank?
and what are teh cons to not having one in an oscar tank?