need advice on changing sand/substrate

[skozzy1]

My 72g has sand/gravel ranging from sub 1/16th" to 3/16" and I purchased some Carib Sea Arag Figi Pink live sand. I want to change out the sand to the new, but I worry that doing it all at once might not be a good idea.
Should I start at one end do it in 2 stages or just go for it and change it all at once.

[iansfishy]

I dont know for sure but if your sand depth is that minimal it is pretty pointless besides for looks. try a quarter of the sand everyweek or so.

[skozzy1]

Yes, that is part of the reason I am changing it out.
I do run an double size skimmer and a filter stack rinsed weekly and have had no water quality issues.

[skozzy1]

The depth is 3 inches. What I listed above is the particulate size. The granules are so big that I don't think they help much with filtration.

[skozzy1]

bump

[Trigeek]

I would say it depends upon how much LR you have. If you have a lot, then you may have enough bacteria to prevent a problem. At 3 inches with a larger particle size, I'm not sure, but I believe you do not have an anaerobic zone. If you do, it is small. However, the substrate does have bacteria that helps break down ammonia and you do have quite a fish load. Also, stirring up the bottom to get the old stuff out will put some junk into the water column. I would change the substrate in sections, maybe a 1/4 to a 1/3 each week.