sand 1.5 years old , replace or not??

so i am in the middle of a total tank rehaul, making it into a mostly acro tank.

i have had this sand in my tank for 1.5+yrs and its been threw some harsh times and high nutrients. it goes from 0.5"-2.5 deep . can/should i start to change it out lil at a time?
is it a good idea to replace sand?


what size sand is best?

i use sugar size and its kinda hard to keep clean.
i am wondering if it would be better to use a bigger grain, so i can use a vacum and get more flow in the tank with out kicking up the fine sand.

what do the few of you that have sand in your sps tanks use. what size?

 

I would do a bare bottom if i were in your position...but thats a good question!

 

I went bare bottom in my sps tank so I could really bump up the flow. If you are going to remove the sand bed it is recommended you remove as little as possible over as long a period as disrupting the sand bed can release built up gases and other organic material back into the water column.