Backyard Aquaponics
A place to discuss aquaponics

hi all..

i am trying to set up a (cheap) system here in sth east qld and have been wondering what would be an appropriate medium for the grow beds.

i hope to be using a variety of troughs, tanks and 1/2 barrells for the gb's..

scoria is as scarce as rocking horse excrement..... and the clay balls are way too expensive... and the scoffing laugh from the hydroponic supply man when i asked about aquaponics...

could anyone guide me in the right direction to what would be good to use... and what to avoid..

loving the forum.... have learnt so much already!!

thanks

Avoid limestone or marble, tends to buffer the pH a bit too high for most people and plants.

Seems many people down under use blue metal (make sure it is clean as stuff that was piled by a road project might have oil products spilled on it.) Granite might also be good though heavy and usually not cheap. I rather like river rock as it is about the cheapest stuff around here other than limestone.

Pea gravel maybe??

Pea gravel is the cheapest by me too. About 3 USD for approx 40L.

Unlikely you've considered it, but don't use wood chips, especially pine of any kind.

River stones have been found to work well, know anybody with a creek you could mine some from? I know they're expensive to buy

+1 for river pebbles. 15/20mil. I used them in my small system and they worked a treat. This is probably obvious but if you contact all your local landscape supplies yards and play them one against the other you can usually get the price down.

wow..

thanks for the quick replies!!

i was at work when i wrote the post..so i was a little too quick..

there is plenty of river stones around here... the mary river stones are mined close to here..

i was concerned that the stones may retain heat esp when it is hot... this i thought might raise the water temp...

i was also being a wuss and after something lighter...

i will look into the pea gravel.. might have a different name here ...

thanks all!!!!

I used what is commonly called "salt and pepper". A light coloured gravel with black/brown flecks through it. I got it because it was the cheapest suitable material at the landscape supplies

Gravel, river rock in my system. But after expanding with new gb's and clay I've got to say clay is great. Even if you just top dress your gb's in the stuff. I used 3 ish bags to top dress a 1000ltr gb today. The temp is better and plants seem to grow better in it.

Top dressing beds? Sounds interesting, what did you use for the bulk of the beds? Have you found the clay balls mixing into the other media during planting and harvesting at all?

Gravel and river rock for the bulk in the gb's. And the clay likes to stay on the top because it is a lot lighter. Threw gravel the wrong way and it ended up on top of the clay and all I did was give it a stir and the gravel disapeared. Will top dress all the older gb's. Gravel and river rocks are cheap but the plants do find it harder to grow. But they will also help support larger plants.

Dufflight looks as thou you could be on a winner with your top dressing

Hey Duffylight,

It sounds good, over a 300-350mm deep bed how thick so you recommend the clay balls and does this mean no root crops? ie. carrots.

In the BYAP gb's I used 10cm's of cycled gravel. So no problems with root crops. You can always use 90mm PVC filled with clay to sit on top if your really worried. The other gb's I have 10cms ish of clay on the top. Mainly for the better temp and the plants seem to grow faster in clay. When the roots make it into the gravel or river rock the plant is allready powering along. The heavy media helps support the larger plants.