changing sand

[robert serafino]

I have i 125 total water 140 i want to change the sand in the front part of the tank. how much can i take out at a time. i want to keep the tank stable. and how long in between each take out.

 

[Diesel]

Basically you can take all sand out in once but don't install the new sand at the same time.
Not sure how much you can bring back but it depends all on your bioload.

 

[robert serafino]

My bioload was high I sold 4 big fish now there is only 2 clowns 2 Cardinals cleaner wrasse and a leopard wrasse