Take the screen shot by doing fn+f2, and then upload it to tinypic.com.

 

pumpkin have same light lvl as glowstone
pumpkin on top

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no light

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light higher up

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it makes no difference wether you have glowstone on the ceiling or ontop of water, if your seeds stay in the soil then its good.

 

This is not true. If the seeds dont get enough light, they will pop right out of the ground. If its wheat, it will simply not grow. It happened to me yesterday. My pumpkin stems were "popping out" (like if I punch them) after a few seconds, and my wheat (in the corners) wasn't growing

 

Ah I thought you mean "if it stays in soil" as in "if its provided with water" :p

But having the light source on the ceiling (3 high), you have more chances of losing the corners, since light distance is affected by vertical changes, losing a few spaces in the edges (light source can be viewed as a sphere)

 

I prefer to put the glow stone over the water, as it blocks any drops that may fall into the water stream.

 

So... it makes no difference in using glowstone or jack o lantern? Couse i also have this project in mind and i didnt feel like spending alot on somthing that can be replaced by a ridiculously cheap material