How hard is it to change a saltwater tank back to freshwater. I would like to set up a large tank for some Dissus but the wife thinks she want saltwater.

Thanks Rick

I dont see why you would run into any problems.... just change the stuff in the filter to go with more freshwater stuff.... I dont know anything about saltwater, but as far as substrate, rocks and decor, shouldnt be a problem, just do a 100% water change and let cycle.

I have done this before. It requires a complete breakdown and new setup. If you are using gravel rinse it very well. If crushed coral replace it with gravel (you may want to look into a planting substrate). If using artificial decore rinse it very well if useing live rock replace it with fake decore, or driftwood and stones. Take the tank and rinse and scrub it with hot water only. Take the filter and replace all the media and give the filter thehot water rinse and scrub. You are going from one ph extreme to another and you want to be sure you do it all the way because anything that alters the hardness of your water now (crushed coral, liverock) will still alter your ph and you want to drop that ph by a lot. For discus you should have a really low ph and a fairly high temp. Also plant it to make sure the discus have a place to hide. Last but not least don't add the discus untill the tank is fully mature, depending on the cycle process you use this could take a few weeks or several months. Good luck and remember after the initial break down/set up take it slow and do your research so you do it the right wayy. Discus are not cheap or easy by any means. If you do the research and plan head and take it slow you should have no problems.

OH yeah, you said you were gonna do discus....lol.... I was thinkin you were gonna do cichlids, wich like my africans, love crushed coral in the tank, lots of salt, almost brackish water.... So, I would think you would be fine with what I said.... but, I dont know squat about salterwater tanks, so take fishnv infomation... he is on top of his stuff.