http://www.amazon.com/Hydroton-Clay-Aggregate-Grow-Media/dp/B000FCPDFA/ref=sr_1_1?ie=UTF8&qid=1312006582&sr=8-1

Would this be a good alternative to coconut husk? Please share your opinion. I am considering this medium because the pellets are round and it would allow much air get to the root system.

those are for hydroponic growers and not for citruses in pot outside

mixed with some peat I don't know if they are going to get along between them

I have a hydroponic setup that is a flood and drain system. I did have a small orange tree in the setup with hydroton but I've come to the conclusion that citrus isn't terribly suitable to that type of hydroponic setup since it grows too slowly.

You don't mix hydroton with anything it's designed to hold a little water and dry out - to be pH neutral and not to shed any particles that would clog a pump in a hydroponic system. Hydroton is also sterile so you need to use a nutrient media.

I do think citrus could possibly do OK in a drip bucket hydroponic system but again since citrus are such slow growers why would you put a citrus tree in a huge drip bucket when you could grow tomatoes?

I think if you are thinking hydroton would replace CHC then I would have to say where CHC stays wet for many hours to a day the hydroton would dry out much much more quickly so its not a suitable replacement at all unless you were watering constantly (my hydroponic system waters for 15 min every hour for 16 hours).

I’m using it at bottom of container to prevent root rot, is working very well.

alright Stormlight since I think you really want to try out the hydroton, here is a way I would suggest it.

If 3 gal is large enough buy this drip bucket (it comes with enough hydroton + nutrients and air pump) and set it up on a timer to say drip for 12 hours a day ??? (not sure how long is good for citrus). I have one of the smaller buckets for some cherry tomato plant and it works great - setup is 30min.

http://www.bghydro.com/BGH/itemdesc.asp?ic=HGSBSPGEC&eq=&Tp=

If you need larger than a 3 gal grow chamber then you'll have to look for a bigger setup. The reservoir is where the water + liquid nutrients are and this setup uses a pumping (with air pump and drip ring). Again not totally sure how citrus would respond to this type of setup but I was disappointed with my growth of small orange tree in a flood and drain setup. Not sure what PPM (concentration of nutrients to use for citrus though).

You would also need to buy a TDS meter to measure the PPM of your nutrient solution. Bubble buckets can also be made if you're handy and found a lot of Ebay. I recommend anything Gen Hydro makes as they stuff is high quality and easy to use.

How large are the particles? About 1cm is the common size I've seen. Anything 1cm or greater can be hard to use when repotting, it's hard to get them inside the large root mass of well grown plants. Being ceramic they should take up and release water, probably not as well as chc, but maybe similar or better than large bark. Is the round shape a disadvantage ?
When mixing with other materials, there may be no strata/structure as with flat particles(bark,chc). Would crushed unglazed ceramic brick be better?
How is your climate ? Is the ceramic going to take up more daytime heat than other materials? Could be good or bad.

Atm, I am just looking for an alternative solution for soil. My problem states below:

I am trying to grow citrus indoor only. So far I lost a Bears lime (1year) and a calamondin (1year). Atm, I am loosing my 6 years old Fukushu kumquat due to root rot. Yes, I bought this big tree last fall and it stay alive and thrive throughout the winter indoor. It was a full tree during the winter months but now it has no leaf left. CHC mix of 5to1 peatmoss with perlite is not working out for me. The soil stay wet for too long. About 5 day ago I repotted and drilled about 20 holes at the bottom of the pot drainage. It has been about 5 days since I watered and the husk at the top feel wet when I squeeze. I have a rapitest moisture meter at 2/3 depth, it reporting a 2.5. The pot is about 6" diameter from the outside diameter of the trunk. I have had 3 x18w 6500k CFL on it since I got it: 14 hours a day. I just order a 400HPS/MH light to see if it makes a different. The temperature in the house is around 80F and 40% humidity. This may be the growing medium I am looking for since have been successfully waterlogged with a variety of mediums. I have also been trying to water no more than once a week.

The plant had alot of buds, flower bud about to burst but somehow all the branches started to die back and killed all the buds. Alot as in 60+ swelling buds. Right now, I have only 1 bud remaining; also having one 18W CFL on it. Should I take my chance and repot again with hydroton? I will attach pictures later tonight.

Well I can say the hydroton is very cheap and does provide a lot of oxygen for roots. One thing I do find is that it doesn't hold up larger plants very easily so some steaking would be necessary. The hydroton would also never allow enough water to grow root rot. However, you're setup would be a little more complicated, I'd get a large bubble bucket with a separate nutrient chamber so you can easily test pH, nutrient concentration (PPM), and temperature. Its readily cheap to raise the temperature of the nutrient solution with submersible heaters but way more expensive to get a water chiller.

I did have a small orange tree growing in my hydroponic setup but didn't get a lot of growth from it (in hydroton).


But if you are getting root rot with the CHC it could be that your root zone temp it too low. Also, if the tree has gone into winter dormancy then it needs a lot less water and fert. I think Millet would say the optimal root zone temp is 76F. Size of container seems to have an impact on how quickly the growing medium can dry out also. Do you have any pictures of your setup?

Right now it is summer. Can the plant go into winter dormancy? Winter dormancy does not involve branches die back. I am loosing about 80% of my branches. I checked he root system. The rootball look very healthy.

Well, its a little hard to speculate but if you keep the tree indoors all the time it could get confused about the seasons. Try to get some pictures up and the experts could chime in. I did see one guy post about having a citrus tree in a hydroponic bubble bucket I believe but otherwise aside from me trying it a bit I don't know anyone that does it.

Stormlight, remember the amount of moisture, and the length of time a medium stays wet is NEVER a problem for a citrus tree. What kills a citrus is not the amount water, nor the length of time, but the lack of oxygen in the root zone. Organic mediums like bark, cedar, pine, and especially CHC hold a lot of water, which is what a grower would want, but they also provide really excellent root zone aeration at the same time. Roots of citrus trees, during the rainy season, are constantly in high levels of water for months and months, and months, with no damage at all. In fact the rainy season provides a great benefit for citrus trees. Good moisture levels, with high root zone oxygen, as provided by mediums utilizing various types of woody chips is the definition of a good medium to grow your tree in. - Millet (524-)

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That is the only only green spot left on any of the limb beside the trunk. I tried to cut back some of the limbs but it seems to still contain some moisture: not fully dead yet.

Millet,
Would a fan/wind bring more oxygen to the plant? I cannot think of anything else causing this problem. I have a pink variegated lemon going through the same situation... now it has a few leaves left after I repotted last weekend. I notice it was shooting new roots out of the existing medium into the new medium (peatmoss 50% /CHC 50%). I went ahead and change to the new mix of 5/1 mix (CHC/peatmoss). 20/20 hind sight it was not a good move . I know i have no bug because i carefully inspect all my tree often and my last 5'x5' mandarin almost lost to scales two years ago so I stay on top of the bug very well. That's the one next to it.


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Here is what my variagated pink lemon located. It has no supplement light here but just the window. I received two more citrus from 4winds Last Thrusday. I tried them immediately with 5/1 mix. After transplant, all the meiwa kumquat buds dropped but it was expected.

Stormlight,

are you sure those lights are too close to the trees and causing some heat problems? Also, when lights such as those are too close they don't spread out much light at all, I think some of those lights need to be higher to spread out the light more. I could also be wrong but it seems that a lot of your leaves are all small . . .

I can see what you are trying to do with the seedlings but instead of lowing the lights so much it might be better to raise up the seedlings are try to have the lights at a more uniform height to get more spreading of light.

What types and what bulbs are those lights?

Stoddo,
The lights for the Fukushu Kumuquat are at least 6"-12" away. Just recently about two days ago, i brought one of the lights closer to the last green spot on the kumquat. The one plant next to the half dead is the Mandarin Orange. It happens to like the light closer. Because as the leaf age, it will drop if I move the light further away. Imo, it looks like a few bottom leaves which are curling down are ready to drop.

I am using Feit x18W CFL, ~1500 lumen 6500k. Those reflector are from Home Depot. I have been using those light since November of 2010. Both plant was thriving during the winter months.

I have really good luck with getting seedling going. I got a few of each Key Lime, Nagami Kumquat, Costco (pink grapefruits), Valencia Orange, Washington Navel Orange, Fukushu Kumquat (from the parent plants), poncirus trifoliate (ebay). I want to learn how to graft.

other experts,

doesn't that look like sunburn on those leaves in the last two pics? The browning on the edges?