[Derpeder]

I have an opportunity to purchase 90 pounds of 'Live Rock' thats been drying sense january so probably not that 'LIVE' by now but its about 1/2 hawaiian rock and 1/2 fiji rock.

He is going to sell it to me for $150 dollars. Question 1. is that a good deal for dry rock?

2 how long will I need to cycle my tank if I add say another 10 pounds of cured or uncured live rock mixed in so it seeds the remaining dry rock?

Any other advice would be good.

I'm setting up a 100 gallon tank and 20 gallon sump.

[Old Man Of The Sea]

I don't get this, why dry the LR? You need first of all to keep it wet or submerge in saltwater. If your just starting a tank to cycle, you do best with uncured LR, it would help in your tanks cycle. If the LR you dried been dried for so long, I not believe any seeds could had survived, for as well, it need oxygen and water currents to do well. For like myself, I now for some 2 years have these reef tanks, that aren't completed as yet. But are with lots of LR and water circulation.

[CSeaSee]

Your rock will still have some beneficial bacteria on it, but it will likely be devoid of anything else worthwhile. Not to worry, though- the bacteria is what you're really after. Yes, the bacteria can survive in conditions you've described. Just expect it to take a long time to become a really good biological filter- you'll need some patience while the rock's bacterial populations become re-established. I'd definately toss in some high-quality live rock as well.
As for the price, it seems really high for what you're getting. I'd pay no more than $1/lb for rock like that.

[leebca]

It's not live rock any more. Best to not call it that!

It may or may not work as base rock. (I'm using the definitional here: What is Live Rock, Anyway?). Maybe it's dead rock now.

Bacteria for the nitrification process is 'free.' You don't need to buy them. They are in the air, in soil, in water -- everywhere. Glass rock will be home to them, too. All these bacteria need is a surface. But a 'holey' and jagged surface is best to create the greatest surface area.

I'd pay no more for this rock than you would for any other dry rock suitable for the marine aquarium. That is, you're getting nothing special from the dried rock.

[Derpeder]

do you have any websites that sell base rock so I can compare some prices.

This dry rock would be $1.67 per pound. I'm just wondering what else is out there.

Another question. Becasue at this point it is just Base Rock will there be ammonia in the water constantly while it is being seeded? so ultimately could I get some live rock, add this base rock and live rock to the tank, cycle the tank, after it is cycled add fish while the rest of the base rock is being seeded? or can I not add fish untill ALL the base rock is seeded?

I hope that makes sense.

[leebca]

Any kind of (marine aquarium appropriate) rock will be home to nitrification bacteria. What live rock brings to it is the ability to also act as a means for an efficient denitrification to occur. Base rock and dead rock can't be made into live rock in the home aquarium, yet each kind of rock will act as a nitrification biological filter. For clarity you need to read these threads:
What is Live Rock, Anyway?
and
Denitrification v. Nitrification

No. Your concept of cycling and adding fish is not recommended. It isn't just getting nitrification going that is important before fish are added, it is maturing the aquarium. What is recommended is that you develop a lot of patience and follow this recommended procedure for starting up an aquarium:
Setting Up a FOWLR Aquarium

There are no good shortcuts if you really want a top notch marine aquarium.

Save your money until you have enough money for all the rock your aquarium needs, then buy and put it in and then pick up where the above reference/process indicates you're adding live rock.