Backyard Aquaponics
A place to discuss aquaponics

BroHay,yes it's the DIA of the barrel or more exactly the DIA of the water surface,in my case these 60l barrels are 30cm DIA so the centre baffle was cut from 10 cm pipe,the length of the baffle is a third of the water depth,mine is 66 cm so the pipe was cut at 22 cm.

Food&Fish,Charlie many thanks,after years of micron tolerance engineering,I find plumbing quite therapeutic and as age is catching up with eye sight not as it was,a fair bit easier......

Picking up barrels tomorrow and will put the information to use.

Thanks,
Adam

More pics,struggling a bit with the lettuce as humidity has been as good as dam it 100% for the last three weeks,this has manifested itself in a Calcium deficiency within these Grand Rapids lettuce. The roots have got really short and stubby in most of the older stuff,which means like today where its going to hit 35c+ they wilt and get stressed,foliar Calcium/Boron mix has prevented leaf burn or any form of necrosis,but it doesn't help the roots,strangely its not on all varieties of plants.
Now then would be a good time to improve the ventilation and make it just that bit bigger with another four metres,which would be just enough room for strawberry production......Hmmmmmm

I was growing mint in the tube but the root system got so big it restricted the water flow, restricted growth at the end and just made a mess,so its gone,to be substituted with Kang Kong,hopefully this will help with Nitrate control as the mint was meant to do,plus its eaten by nearly everyone here.Celery is still hanging in there even with the stupid humidity and temps,seems to take an age to germinate,but its well worth growing as the price per kilo has gone up dramatically,Lettuce fetches a Dollar a kilo,Chinese Celery at the moment is up to $7.
The top pic is a single Chillie plant growing in the DWC,its being used as a comparison to the same Chillies being grown in the Dutch Buckets,interestingly no sign of Calcium deficiency,same trough as the Lettuce.

Have you considered ebb and flow to extend and promote root growth, Dasboot? As in ala Cornell studies

It's always good to watch Andy laying some pipe...

I will do the Googly thing and read up on Cornells studies,everything is worth a consideration.

Two types of lettuce,half grown Grand Rapids and younger Rocket,look at the difference in the roots,granted the Grand Rapids was about as bad as i could find some of the others are better than this,but this does show the problem.I think its Calcium but open to other views,by Foliar Calcium there is no necrotic spots or burning of tips or edges,but when the temp goes up it wilts badly as it just cant supply itself enough water.The roots on the Rocket are 60cm long and when there in the water fan out beautifully and look as you would expect them to look,both plants are from the same trough so the same conditions,the Bok Choy from this trough had similar roots to the Rocket.

Ill try find you the link, Andreas. Ive got it in my notes somewhere. Something about the tidal water and roots searching/stretching for nutrient and creating a good root stock. Might not have worth but thought Id suggest a read up as I don't know if it holds any merit.

All looks good in my eyes champ.

Seems to me, that what is needed is a good lab analysis done on the water and what nutrients are available and what ones aren't.

When you ask a lab to do this make sure you tell them what your system your using to grow in, and what types of plants you are growing, that way they can give you a better suggested solution to fix everything.

Are you suggesting to do flood/drain in the DWC?

thjakits

Yep.

Itr may be somewhere in this one, Andreas but I haven't gone through it thoroughly sorry. There is some good info on nitrate uptake in relation to light levels etc, all good reading.

http://www.cornellcea.com/attachments/Cornell%20CEA%20Lettuce%20Handbook%20.pdf

....that's what I posted (..some time ago), I would want to try out eventually - however, not really concerning root-stretch, but to see, IF with this method I could eliminate air-feed into the DWC...
[As was demonstrated on many threads on here, DWC plants do a lot better with air...]

[If you already use air for water turn over - airlift - not much reason to eliminate it in the DWC, but if I use a water pump, I would want to try to eliminate parallel systems, if possible...]

I am planning on a pvc structure on which the floats can rest during the drain cycle - let them sink an 1" or so, before they settle on the structure - drain some 4-5" and refill (I think a siphon system would be perfect here....) - plenty of aeration and roots get stretched for sure!!

The detail question is, what EXACTLY is it the air bubbles DO in a regular DWC??

-root movement?
-oxygen to roots?
-loosen dirt particles?
-all of it?

-can all this be replaced by ebb/flood?
[Obviously - ebb/flood has a WAY different dynamic on the system than air-bubbles, so it will be interesting to observe the differences...]


Andreas - .....YOUR next project was just served!!

Cheers,

thjakits