Howdy Legalinaz, Get a magnifier and look at the trichomes, if they are mostly cloudy, You can expect some good results. If they are mostly clear, then the effect will be more 'racy' or 'speedy' and might not be worth it, but there is only one way to be for certain, try it.
Did the water in the reservoir have a bad smell, either rotten or musty? Are there any other plants in the same reservoir, with the one that 'croaked'? I had one plant that choked out it's sister until she was the only one left in the reservoir! I'm about to start my 6th grow and the best advice I can give is;
1. Keep the water well aerated and cool, between 65-70 degrees F.
2. Keep the air circulating and the temperature between 70-85 degrees F.
3. Keep accurate records of the nutrients used, water and air temperatures, humidity (both in the grow area and outside of it), and of any occurrences and actions taken (bugs, mold, discoloring, etc.). A photo record also helps.
Good luck with Your grow.