Newbie needs questions answered for his 125gallon tank hes starting!

Yes, DT is display tank.

To clarify, you have to understand that curing can not take place in a tank with anything live in it. I'm not talking about curing rock that's already live, I'm talking about your scenario, in which you're going to make your own rock out of portland cement, sand, gravel, etc.

When you research the process, you'll learn that after you make this rock, it has to be "cured." This means that the basic (i.e. not acidic) elements in cement must be neutralized lest the freshly made rock kill everything in the tank. In a nutshell this means that it must soak, be rinsed, soak, harden, soak, etc.

Since you don't currently own or operate a marine aquarium, there's no reason not to use the aquarium you have for this process. (Some might debate that, but. . . . .) While your newly made rock is curing and becoming inert, you must not have fish or corals or any other life in the tank. During this period you will use powerheads to circulate the water and the surface, to allow for the gradual release of pH-lowering, toxic elements from the rock. All the while, you'll be changing the water often, to export these pH-lowering toxic compounds and create an aqueous envrironment conducive to the osmotic action necessary to make your rock suitable for a fishtank.

The beneficial bacteria of which you speak will not come into play until your tank becomes a living environment. Once your rock is inert, only then will it be suitable to house the bacteria you wish to harbor.

To sum it up--you'll make your rock, and cure it in the "dead" fishtank. You'll change the water often enough to take weekly pH tests, and when the pH stops falling and stabilizes, you'll know you're finished.

When you're finished with the cure, only then will you add saltwater to the new tank, and begin your cycle. Only then will the environment be suitable for life, suitable for nitrifying beneficial bacteria, and suitable for our purposes.

As for live rock in the sump, I'd avoid it. It will get loaded with gunk, and start to pollute the works, rather than filter it. I'd advise keeping the LR in your DT where the flow is more ample and the rock is less likely to become laden with detritus and other nasties. The sump is better utilized for mechanical filtration (if you use it), your skimmer, heater, and other things preferably kept out of sight.

Hope that helps.

 

IMO a LFS that recommends a seaclone skimmer and a rio pump is only looking to move their own crappy merchandise. I would go with a mag drive pump and an ASM, euro reef, or SWC skimmer rated for at least 100 gallons over your total system volume.

~Will.

 

Looks like alot of good info. One thing I wanna mention about curing the DIY rock in your tank. I made alot of DIY rock, and cured it all in a plastic trash can. During the curing process the water would get a nasty film in between water changes. This is now all over the inside of the trash can, and after seeing how mine went, I wouldnt want that to happen to a display tank, it could lead to some serious cleaning. Just a thought.

 

I would personally recommend some live rock. You can still indulge in making additional rock for fun. Live rock will bring spectacular organisms to your tank that will not only be fun to observe but be beneficial to the fish you stock. It will also expedite the process of your homemade rock to develop the bacteria and algae necessary for a healthy tank. However, live rock can also bring intrusive hitchhikers....so be careful on your selection. Have FUN!