How much rock?

Awsome ya it prolly won't be that much rock but just rather over estimate thanks for all the help

My 150g has about 3inches of crushed coral and about 200lbs of granite rocks on top of that.
No problems in the last 5 years or so that I've had the tank but I suppose something could go wrong any day now....
Glass is a lot stronger than most give it credit for. Just try breaking an old window with a hammer sometime. You'll be amazed at how hard you have to hit it before it breaks!

weight <> volume. Tufa has minimal weight, plenty of volume. Granite has plenty of weight, minimal volume.

Safety first, imo. YMMV. But i wouldnt want to be working under a tank with that many rocks in it.

You will be fine.
Think about this: For every rock you put in you lose a corresponding amount of water. Although rock weight does not equal the weight of water,adding 100lbs of rock doesn't mean your adding 100lbs of total weight to the tank. After you figure in the displaced water you might only be adding 50lbs of total weight to the tank.

Seems like a lot to me. I am not a fan of that much rock with sand as you can get dead spots where there isnt any water flow and then these spots turn very foul, anaerobic, produce h2so4 (hydrogen sulfide, AKA "egg water") and if disturbed your fish can suffer or die.

If left undisturbed, the dead pockets are fine. The problem is most cichlids disturb the sand.

Also, consider laying the rocks directly on the glass.

Don't get me wrong, I used to use a ton of rock in bare bottom tanks. The most I ever used was probably 150 pounds or so. Good luck.

Yes

I went to the Landscaping store the other day and liked the small to medium granite boulders (baseball-head sized) but they are very heavy im thinking im going to need about 400lbs of it for the look i want. The tank is a 150 gallon 4ftlx2ftwx2 1/2 ft t is this going to be ok weight wise with around 100lbs of cichlid sand?