"live" sand substrate benefitting plants?

i am so confused! i went into petco today to get some sand substrate for my 75 gal. i never bought any, but here is the reason why: they had a choice between "live sand substrate" which is supossed to benefit the health of plant roots, and then they had coral substrate which is rougher and bigger so it won't get sucked up by a gravel pump (according to the pakage). i want the sand substrate because it is finer and looks nicer from my perspective, but i was just wondering if that whole "benefits plant roots" is true or not, and if i choose to get the substrate, it has water in the bag....do i dump the substrate AND water into the tank, or do i dump out the water and wash the substrate before adding it to my 75 gal?

jtburf said:

do not get salt water sands, usually they are bad for fresh, do you want it to be light, naturaly, or dark?

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what do you mean? the bag said "good for fresh and saltwater aquariums......is this not true? and i want it to be dark. i picked out this black sand substrate that was really cool. i am also going to have an all black background....or maybe not. depends on what other backgrounds i can find.

oh. so then what is a good brand of substrate that IS good for FW tanks?

jtburf said:

I use a brand made out of taiwan in a greyish silver bag with orange writting, it looks like littlew chocalate chips, plant like it and it is realatively cheap, like for me $20 for 60#.

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u say that it is like little chocolate chips? then does that mean that it is NOT the same consistency as a fine sand substrate? because i would like to have more of a small/fine substrate then a rough/big one.

they sell the consistancy i am looking for then? ok. i will check it out. thanks!