what went wrong

[Myka]

Originally Posted by whistlerskipro

I did a 50% water change yesterday and was told by the same person I should cover it up and let it have no light for 3 days.

Hopefully the picture was downloaded however though it looks like the water is green it is NOT

If the water is not actually green, what is the purpose of the no light period?

Originally Posted by whistlerskipro

Sorry about the confusion: I added the dead coral to increase the overall filtration. I didn't think the original 40lbs was enough. More is good?

More is not always better. Your friend may have been right - if you have too much rock then it hinders flow and creates dead spots. Detritus settles in dead spots and this can lead to issues.

I believe by removing some of the original LR (two weeks ago) caused the tank to crash .

What is your definition of "crash"? Did all the fish die?

Question: Can base rock (the dead coral) replace the old established LR in two months? I don't think so.

No, you are right, dry rock can't replace live rock in two months, it needs much longer. You had plenty of live rock left though, so that shouldn't actually be an issue.

So I am thinking I am now dealing with my tank trying to re-establish itself.
Maybe I am completely wrong and it may be something completely different. I am very new at saltwater tanks.

I think that maybe when you were messing in the tank you disturbed areas that aren't normally disturbed (dead spots from having so much rock) and caused some nasty stuff to get in the water.

If your tank is cycling again you will have an ammonia reading. Have you tested ammonia? No ammonia means no cycle.