ctbuxton

[ctbuxton]

A silly question perhaps, forgive my novice-ness, is vermiculite as suitable for the growth beds as the expandable clay pebbles? I gather the pebble cleanup of rotted plant roots after a few months of growth is tedious. The vermiculite could be replaced with fresh and the old recycled into the ornamental portion of the garden. Is this an over-simplification, I gather the clay pebbles are a key component of the bio-filtration, but if there is a separate bio-filter step does this circumvent the problem?

[grassroots]

Hi ctbuxton, clay pebbles are one type of media for bio-filtration, there are other types for example gravel, k1's, shellgrit, oyster shells, etc. I don't know much about vermiculite, I have heard that it gets soggy. If you are growing plants in any sort of media, there is going to be a build up of roots etc. Others with more knowledge might have different or better answers.

[ctbuxton]

Thanks for that, soggy doesn't sound like it would be good in the veggie grow beds. 1000 questions -1

[bunya boy]

Hi CT,
I personally wouldn't use Vermiculite or Pearlite or anything similar for Grow Bed media.
Anecdotally: it becomes waterlogged and will not allow for the top surface to be dry thus causing stem rot; it will always contain floating particles which are small enough to pass through the siphon/pump/pipe work and get into the fish tank where it can cause a problem with fish eating it! It will always float and move as a mass, not good for plant growth I would presume and it allows (by being wetted right to the top surface) algae growth in your Grow Beds which takes away nutrients from your plants that you are trying to promote.
For my Bio-Filtration I use a small layer (25 to 30mm) of Lump or natural Charcoal on the bottom of my Grow Bed, followed by 250 to 275mm of 20mm drainage gravel and then topped off with a 30 to 50mm layer of Canna Clay "pebbles". The water comes up to within 25mm of the surface of the Clay Balls, leaves the stems dry but waters the roots. The roots do extend down into the gravel but don't reach the charcoal layer. This is after about 8 months growth and I have not had to clean any media; I don't expect to do that for a couple of years yet and cleaning Clay balls is simple according to Gary and others who have done it.

The Plants are doing fine (Parsley, Curry Plant, Chives and Malabar Spinach) even though they don't get any direct sunlight!! But I do tend to kill a lot of fish from my own stupidity. Go with Gold Fish, mine appear indestructable, Jades and Sleepy Cod weren't so hardy!!
Cheers IanK

[ctbuxton]

Thanks for that Ian, I like the addition of charcoal that makes a lot of sense. Does that all imply that your system is wholly balanced without the need for a separate bio-filter chamber, the media's layering is sufficient? In my mind, the fewer steps all the better. Shame about the Jade Perch, I thought they were fairly hardy, is your winter much cooler than CQ coast?

[bunya boy]

CT,
Yes, I do not have any other external bio-filtration. The Grow Bed media is sufficient for my stocking rates. I did trial a Cyclonic Prefilter between FT and GB, it worked fine but wasn't really needed, so it got removed.
The Charcoal is a trial to see if it made any difference to the water's pH (It didn't) and to remove any heavy metal etc. from the Town Water in the first instance. (It has seemed to!) So I will continue to use it. It is not Activated Charcoal, just Natural or Lump Charcoal used for BBQ's etc.
The Jades and the Sleepies didn't die from temperature (the water temperaure is at a steady 20 degrees C in my insulated tank) or anything to do with cold etc, just me being stupid, giving them a "glass" of Red, overfeeding with Bad food in one night of alcohol induced madness!

Cheers IanK

[GaryD]

Hi Ian,


I did trial a Cyclonic Prefilter between FT and GB, it worked fine but wasn't really needed, so it got removed.
Don't throw it away......it will come in handy when I finally lure you over from the dark side.;)

Gary

[bart]

hi guys vermiculite and products like perlite are much better in wicking beds and as a suplement to your normal soils in a flood and drain they tend to compress together and that causes these products to loose some off there water holding ability and to become soggy dont rule out using scorria in your gbs much cheaper to hydroton{clay balls] and there's lots of micro nutrients in scorria and none in the clay balls

[ctbuxton]

I will look up scorria! The clay media is very pricey, I guess one could layer the GB with river gravel and top it up will clay media, reduce the weight and the price?

[ctbuxton]

I'm glad the BBQ coal is safe for use, I was curious, obviously not the self-ignite variety. We would probably use bore water or rain water. Well now I'm advised not to share any wine or Macca burgers with my fish or crustaceans.

[holidaymatt]

EDIT: started to ask a question and saw it had already been answered

[GaryD]

Hi,


I will look up scorria! The clay media is very pricey, I guess one could layer the GB with river gravel and top it up will clay media, reduce the weight and the price?
This is fairly common practice. Not only does it reduce the weight and cost, but it also provides a secure base for plant roots and it's much nicer on the hands to plant seedlings into clay pebbles, too.

Gary