brace on the center on 90 G necessary?

If I was you I would leave that brace in the tank. There is a reason its there. Obviously tank manufacutres would not take the time/money to put something on the tank that was not needed or benifical.

The main reason that brace is there is to keep the front and back glass panels from bowing out. As the tank fills the amount of pressure being put on the long glass panels increases. Given that the glass panels are a few feet long they are weakest in the middle. Belive it or not but that thin plastic brace keeps the tank from bowing out in the middle of the span of glass.

I know of one person who removed his center brace only to find his tank bowing over 1" in the middle. This bowing will put extra pressure on the side seams and can advance tank faulure.

I had have a 45 gal tall tank that I got used and the center brace was split. WHen the tank was empty you did not notice the brace was split as the two ends meet up and the crack was hard to see. After adding water to the tank the spit was very noticable because their was about a 3/4th of an inch gap between the two ends of the brace.

I replaced the top frame of my tank to fix my problem but I am aware of others who have used acrylic instead of the black plastic and I know of another person who has used stainless steel rods to brace the center.

Agreed.

i Also have a 90 gallon tank "Allglass" so when i got it, it had the centerbrace , Black and i did not like it at all, Becouse un run 3x 175 halides, So one of the halides sat right on top of it. .

So i pulled out the hack saw.. and wellaa! .. Problem solved, Look great.. untill i put water into it.. as once i started to fill it i heard this weird Creaking sound.. SO i stoped.. i messured from front to back all the way across my tank, and in the center where the brace was it was about 1/4 inch difference.. So drained the tank and tried to glue the brace back in and of course looked like Crap and did not work.

So i had to remove the Whole Black trim off the top and buld my Canopy around it the tank to make up for the brace i removed.. Trust me was not the best idea i had ever come up with

on my tank (125gal) the brace also supports the glass tops since I have 2 seperate tops. I suppose that isn't as important if your going open top but since I don't have a canopy i need the brace.

gW

yeah, i had a tank that bowed alot, so i siliconed in a piece of clear glass that was 4 inches or so wide in the center of the tank and at the top and it held really good, plus let light in... just my 2 cents

Depends on how thick the glass is.