wood charcoal as medium...
 

hi guys

am new to hydroponics and i have trouble finding traditional medium for growing, i was wondering if i can use coarsely crushed wood chip charcoal as medium ?

thanks!

I wouldn't use charcoal as medium. If for no other reason, as it dissolves in the water would turn it black and leave residue that is likely to clog the pump. But I'm sure there are other drawbacks as well, like nutrients bonding with the excess carbon and becoming unavailable to the plants. I also wouldn't use the type of charcoal for filters (it's a completely different type of charcoal), this charcoal is specifically used to take elements out of the water, that would defeat the purpose of the nutrient solution.

But you could use regular wood chips (no charcoal included) even sawdust, as long as it's untreated. You just don't want it treated with herbicides, pesticides or fungicides. You also don't want any other chemicals in it like paint chips. Lastly, if unsure I would soak some in water, then test the pH every day for a week or so, just to be sure it was pH stable.

thanks for the response, i can't find expanded clay balls here,
can i just use crushed clay pots or crushed corals?

I don't know about using crushed corals, I think there would be problems with that. But crushed clay pots should be fine. I would try to break them up into about 1/2 inch sizes pieces, put them in some type of tumbler (to round the sharp edges that I could), then wash thoroughly to get rid of all the clay dust. You may need to adjust your watering schedule depending on how much moisture they retain. Low fired clay will hold more moisture than high fired clay will. High fired clay is more like dishes or tile and don't retain much moisture at all, but most planters/clay pots are low fired.

They usually line the inside of these pots with some type moisture barrier to keep them from soaking in too much moisture, but that wont be a problem when their all crushed up. You can also use most rocks, they don't hold moisture though, so you would need to water frequently. Also I understand that regular sand is commonly used with good results (for drip systems).

thanks for all the help GPS, if i plan to use a NFT setup to grow, will the media play an important role in the system? do i need media that soaks up water? or do i need media that only supports the plants?

It all depends on how you design it and set it up. You can run a NFT system with little to no growing medium. Depending on what you grow, it may need additional support that you can provide from above. Though the use of a growing medium can provide more moisture to the main root ball. The roots actually wick up the nutrients in an NFT system, but as they do, the growing medium (if used) will be able to hold some moisture as well. In either case until the roots are long enough to reach the water supply, they wont wick up anything. So you will need to adjust the water level accordingly as they grow.

You can also use river rock if you have that available. I've seen some set ups with marbles.

I say go with river rock or the gravel in your drive way every time.