Need help converting from a saltwater to freshwater tank..

[tampa4]

I successfully had freshwater fish growing up, but moved on to salt about 5 years ago. Though I love saltwater fish, I'm switching back to fresh mainly due to the time needed to maintain a saltwater tank, and the expense involved. And hey, freshwater fish are very cool in their own right. But anyway, I have a 70 gallon tank with a live sand bottom, live rock, and filter with protein skimmer. I'll be selling my saltwater fish to a local store today, and then getting ready for the switch over to fresh. With that in mind, I have a few questions that perhaps a few of you can answer for me. First, can I keep my current live rock and sand and use it in a freshwater tank? Next, if I shouldn't keep the live sand in the bottom, what kind of base substance should I use? (gravel, rocks, etc) Finally, I assume regular tap water, that has been treated of course, is perfectly fine to use? (In the past I never had trouble using tap at all---but I just wanted to make sure.)

Well, thats about it I guess. Oh, FWIW, I plan on starting out with a few Bala Sharks, a cichlid, and angelfish, and perhaps a discus or two. Any comments on these fish (and their interactions) are welcomed as well. Thanks in advance everyone.

 

[liv2padl]

First, can I keep my current live rock and sand and use it in a freshwater tank?

no. it will die in freshwater and the toxins released will pollute your tank.

if I shouldn't keep the live sand in the bottom, what kind of base substance should I use? anything you like.

I assume regular tap water, that has been treated of course, is perfectly fine to use?

yes

I plan on starting out with a few Bala Sharks, a cichlid, and angelfish, and perhaps a discus or two.

bala sharks do best when kept in groups (they're a schooling species). moreover, they grow to a foot and a group of them is too much fish for your tank. a cichlid ... there are thousands of 'cichlid' species and the one you get will determine whether or not it will do well in your tank. angels ARE cichlids. discus ARE cichlids and should also be kept in groups of at least 6. such a group will fill your tank. if you want discus, get 6 of them and call your tank complete.

 

[tampa4]

Thanks and one last question. I'm thinking of using my existing saltwater filter to help cycle my new tank. Is this okay? Either way, I plan on starting with a couple of hardy fish to help cycle the tank as well.

 

[liv2padl]

the bacteria which cycle a marine tank are different than those that will exist in a freshwater system. thoroughly wash the filter, start with new media and start cycling as from scratch.

 

[Rbishop]

You should consider doing a fishless cycle. Also test your tapwater to see if you have ammonia levels in it to begin with. Ensure your conditioner handles chlorine and chloramine.