[Cawley]

I had a 150 gallon planted tank, while moving i sold the fish and plants. A year later I want to set it back up. Do I need to replace the substrate or can I use what's already in there?

 

[ytro]

What type of substrate is it? Soil based/gravel/sand?

 

[minorhero]

I had a 150 gallon planted tank, while moving i sold the fish and plants. A year later I want to set it back up. Do I need to replace the substrate or can I use what's already in there?

You can reuse it. It doesn't go bad but unless you cleaned it before you took it down it will still have any mum or other debris in it (now obviously dried out). So expect some clouding when you first fill it. Some water changes and gravel vacuuming will take care of it.