complete gravel change
 

I have a question about gravel.

Can anyone suggest approximately after how many years (1, 2, 3, - more) should one have a complete gravel change in a large tank? Does it need to be thrown away, or can I just rinse or disinfect it?

Thank you!

I don't think that you would ever want to do that. The older a tank gets, the "better" or more colonized by bacteria, the gravel gets. Changing all the gravel is just an invitation for a mini cycle. As long as your water quality is always fine (0 ammonia and nitrites, and low nitrates) there should be no need for this.

yeah i would wonder why you would need to do that.
never heard of it myself. ???

As long as the gravel is cleaned using a gravel vac when doing water changes to prevent a build up of gunk over time, there shouldn't ever be any need to replace it.

If the gravel is looking nasty take some out, swish it in some tank water to clean it, then return it to the tank. Keep that up until all the gravel is rinsed. Do not use tap water to rinse it in.

There's really no reason to ever replace gravel, it's just rocks.

Thank you all ever so much for the answer!

I was just in two minds. Knowing that one of my tank was established a very long time ago, and noticing that cories do not do very well there, I thought that could be the gravel's fault. The tank is cleaned with a sifon regularly. Other fishes and snails are fine. The cories must have a diferrent issue.

I have also heard that some people do a complete rinse and even change, but they are not knowledgeable in this hobby. So I decided to ask.

There's no reason you can't rinse it so long as you do it in tank water but if you're vacuuming it regularly it should stay in good condition.

the corys would i have no doubt prefer sand,if it were
possible either introduce a small sanded area,or change the tank to sand.

Cories don't do as well since they like to sift through sand for their food and gravel wears down their barbels.

You are absolutely right about corys and their barbels. I have very tiny gravel in all my tanks taking the corys into consideration. But it might be a bit rougher in this particular tank. I will get some sand for them;)