Are regular decor rocks safe in a sw tank?

I'm setting up a 15 gallon sw tank and have some nice decorative freshwater rocks leftover from another tank,they have been washed and dry for several weeks.But i'm wanting to put a couple fish with some liverock from my other reef tank,but it's only gonna be a couple peices with some mushrooms and palys on them.I want to use the decor rock to help build the rock formation(so i wouldn't have to go and buy baserock as the closest lps that carries it is over 30 miles away)but i just would like to be safe and ask first.Thanks

 

what type of rocks are they? im guessing pretty large if your going for base rock. A cool thing that im going to do here soon is DIY live rock, i don't have the link on this computer but google it, I think the thread maybe on here too, its quite nice and in 6months or so you have more live rock...

 

I'm not using them for live rock,just for structure,but yea they are of decent size,i know there aquarium safe,but pretty solid(not porous)mabled look to them.I had em in a freshwater tank for several years.

 

Not all aquarium safe rocks are reef safe. What do they look like? Are they red? They could be lava rocks which will leach metals into the water which at least will irritate corals.

 

its ill advised as these rocks may leach stuff in the water heavy metals, silica etc. i wouldnt.

 

i would say bleach them just to make sure and then rinse rinse rinse, but even if your using it for structure, if it see's any light you will most likely grow coraline algea on them and the'll become "alive" anyways. I would say your safe.

 

Some types of rock leech stuff into the water.. even days/weeks after being put into the water. So bleaching it wouldn't not always necessarily work. Some rocks have to be placed in a vat of circulated R/O water and 100% water change should be done daily for up to 2 weeks.

...but then again it does depend on the type of rock you are using.

 

I figured they would have been leached out by now after being in a freshwater for several years?Well fudge.....Thanks and k+ for the replies.I have some lava rock thats been in my reef tank from the beginning,this same store i go to sold it to me as dry baserock.But most of it is black/white marbled,and the other has a crystal look to it.

 

Oh- I didn't realize they were used in a freshwater tank previously.
They should be good to go if thats the case- but also be warned that if the freshwater tank these rocks were in was ever treated with copper, you're going to have some problems keeping inverts.

 

Noooo they've never been treated with copper.Never used it before.So mabey i am safe then?Great point though!! Thanks