If I change the sand will my tank have to cycle

[fishykid9212]

I have this crushed stuff for my substrate and i just got a bunch of sand to replace it. Can I just keep the fish in there or does it need to cycle?

 

[LoyalConvict]

What size tank? how much live rock? I'd rinse the crap outa the sand before i placed in the tank, and put some tank water in a dif tank along with the fish and let the sand settle before putting the fish back in. I dont think there would be much of a cycle. I set up a 75 with just 30-40 lbs of rock from my 90 and had didnt have a cycle. but others will comment and give you more insight and dif. opinions

 

[troylee]

You need to remove the current substrate slowy over the course of a couple weeks or your asking for disaster....just by stirring up the sand bed can make a huge mess and major cycle.....there is no problem with replacing it just got to do it very slowly......

 

[wisdan92]

I went through this about a year ago. The way i did it was to use a disposable plastic cup (16 oz) and remove several scoops a day until i got the tank to bare bottom. then start to reverse the process by rinsing a cup full of new sand at a time and lower the entire cup of new sand all the way to the bottom of the tank and pour it out slowly....the clouding is very minimal if u only do several cups worth every few hours. it is very time consuming but by doing it this way i encountered no ill effects on my tank inhabitants.