Uh oh... chlorinated water made it into the tank
 

So while I was away in Vegas (brought home $250) someone topped up the sump with about 3 gallons of tap water. The tank and sump together are about 175 gallons. I do not have any fish or corals yet, the tank was just finishing its cycle from initial setup about 6 weeks ago.

How bad is this, did it kill all my love rock (120 lbs)? Should I do a very large water change or can I just put in some de-chlorinator? Anything else to worry and stress over?

Please help!

Do nothing, it will be fine. The chlorine will just evaporate out with water agitation anyhow. FWIW I top up my FW tank every day or two with anywhere from 3g to 5g straight out of the tap. I've had reef tanks where I ran the water straight out of the tap for topup as well. No chloramine in Calgary as yet so no worries there.

Add some Prime (or whatever de-chlorinator you use) and keep a close eye on the water quality parameters. A 25% water change wouldn't hurt either. Shouldn't of killed off all your live rock by any means but it probably effected some of the beneficial bacteria that was starting to build up. You might notice your tank go through a bit of a cycle again.

3g in a 175g system isn't much so I wouldn't stress to much about it, just keep an eye on things and wait awhile longer before adding any fish or corals.

You are a brave man Tony!

I do the same thing but with 1 gallon max at a time.

Unless it was done yesterday, the chlorine will be gone now anyway. Do nothing, you're fine.

I was going to say you're worrying for absolutely nothing but maybe I'm the one who's wrong. I wouldn't willingly do that but I don't think it would have done much at all.

All my water comes straight out of the tap , and we have a decent amount of clorine in our water .Ive done some big water changes with it and never had any problems with mini cycles or anything ,zoas , rics ,acas , and duncans dont seem to mind either.

Thanks all, I'll sleep better tonight knowing it wasn't as catastrophic as I thought it might have been. Water test showed that the parameters were unchanged since last tested. I added my first critters today.

Let the fish gazing begin!

And thanks again for the advice.

Too much worrying is why people spend sleepless nights and too much money than they need to in this hobby IMO.