Replacing substrate

[frankieg2293]

Thinking of replacing sand to help with my nitrate and phosphate problem

my question is. Do I have to buy 100% live sand or can I buy 50%live and the rest dry?
Also how much sand should I buy for a 220 gal 72x30hi x 24?

 

[blaxsun]

You can buy whatever you want, but you didn't indicate if this was a live (stocked) tank? Without knowing how much sand you have in there to replace it would be hard to say.

 

[frankieg2293]

You can buy whatever you want, but you didn't indicate if this was a live (stocked) tank? Without knowing how much sand you have in there to replace it would be hard to say.

It is stocked with fish and a few crabs and snails ... I took this sand from an 7 year old tank. I believe this is why my nitrates are so high
72” long by 24” deep about 2 inches thick this is as much as I know about how much sand I have. Any thoughts?

 

[blaxsun]

As that's similar to my tank, I'm guessing four 40lb bags (I used three 40lb bags = but my substrate is only around 1.5" deep).