Lava rocks as medium?

Discussion in 'Hydroponic Growing' started by akp2369, May 6, 2015.

  1. I boiled some lava rocks for medium but haven't added them yet because I'm still not sure on it. Anyone have any experience with it?
  2. I have to use them on my hydro system and they kind of suck, you need lots of tiny pieces at the top to block off the light.
  3. What about getting sediment or messing with the pH?
  4. You do get some sediment, if you rinse them off it shouldn't be much, doesn't cause any problems for me.
    If they are clean they won't mess with your ph.
  5. They are very acidic and tend to stay that way, just my opinion
  6. I didn't use them. I'm not even sure if I'm going to stick with hydro. I think it's just too much money to maintain and keep properly.
  7. Oh please APK, don't give up yet, I'm having a lot of success with my hydro setup.. and one you get going and have the stuff, it's not a whole lot to maintain.. But, I do understand the frustrations that come with it.. you can get going and do a whole cycle with 400$
    Money for what? The only cost I incur for proper maintenance is the cost of the nutrients.
    Set up cost, now that's a different story. But maintenance cost?
  9. It's more like I need to get my first grow underway so I don't have to spend money on smoke. I want to be fully situated before diving headfirst into this lol
    But you said it costs too much too maintain and keep properly. As str8jacket said, the only cost is nutrients, (other than electricity).
    What do you need to buy? DWC costs hardly anything to set up. A container with lid, net pot, clay balls, air pump, air lines, air stones, and that's it 
  11. #11 str8jacket, May 11, 2015
    Last edited by a moderator: May 11, 2015
    I can understand that.
    You could always grow in a soil-less medium like 50/50 perlite/vermiculite to get a a feel for using hydroponic nutrients.
    That's what I have done short term when I had to tear down, relocate and re-setup.
  12. #12 GoldGrower, May 12, 2015
    Last edited by a moderator: May 12, 2015
    I'd like to try a perlite / water retaining gel mix. That way you might not have to water so often. I have never tried it though so can't recommend it. I'm thinking it might be good for beginners because the gel  should stop over or under watering problems opposed to soil I mean. Have you heard anyone trying this? 
  13. It rooted good. It seemed to really take off too. I will probably stick with it. How is it looking so far?
    Another question quick is water temperature. I don't have a way to control it really so I mean is room temperature water adequate to use?

    Attached Files:

    I'm not concerned with my reservoir's temperature unless it reaches 21℃, that is when ill start putting bottles of water in the freezer. Reflective and insulated cover on top of the res can often drop the max temperature buy a couple of degrees
  15. OK that sounds great to me. What about water level? I've been told a few different things.
    This depends on what's in the net pot. If it's just clay balls and the net pot isn't too big then you may as well fill the reservoir right up, I brim mine when I top up.
    If you have rockwool or another starting cube that holds on to too much water then you have to adjust the waterline until you get it where it is not keeping the rotwool saturated all of the time. Once you get a decent amount of roots coming out of the net pot you can raise the waterline without any problems. Some people have their waterline under their net pot causing the clay balls to dry up and eventually the roots too. If the roots dry they stop functioning as roots and basically turn to stem. All this does is essentially make your reservoir smaller
  17. This is a photo of some roots that were kept in a res with a low waterline (not mine btw). You can see that the roots have dried up and turned to stem, while the roots only thrive under the waterline.
    Here is some roots that were kept in a res with a high waterline. You can see all the hard working roots right up to the net pot 
  18. I tried lava rock as an alternative to hydroton. Better but lacking as it breaks down too easily
    I then tried polished ornamental rock from the Dollar Store.
    Drains quickly
    Keeps air in root area
    Helps keep moderate root temp
    Easy to remove after harvest
    Easy to clean and reuse

    Attached Files:

  19. That's an awesome idea for the rocks. I will go pick some up today. When can I add nutrients to the res?

    All I have right now is the fox farm trio and a little Neptune's harvest fish fertilizer.
    I keep my seedlings in empty water for a week and then bump up the ppm to about 150-200 for a week and then put it up to 250 and begin checking to see if the ppm rises or falls day by day, and adjust accordingly

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