Backyard Aquaponics
A place to discuss aquaponics

Interesting to hear about the gulping air. I always said that's what he was doing, but never believed it, cos let's face it. He was a fish! :-)
I like to learn something new every day Janet, and my day's only just started. Thanks. :-)

Steve,
I had stopped testing for ammonia some time ago as the level was basically NIL. However I have measured all 3 Nitrogen compounds each day since I started adding the urea and ammonia is still NIL to perhaps a trace each day, nitrite is just a trace( which is a bit of a surprise as it has been basically nil for several months) and Nitrate is once again detectable- probably about 10-20ppm. I reckon that means that the biofilm is still working just the way it should.
pH has really not changed much- a gradual reduction from about 8 in the beginning, 3 months ago, to current reading of 7.5-7.6.
I have planted parts of each growbed so for the small number of fish I have got 3 x 1200 litres of gravel which is probably much too much for the little fishies poo production. I would request more excreta but unfortunately I don't speak catfish lingo!
I intend to add Silver perch to the mix as soon as I can get some- this was my original plan based on advice from this forum. Plan is for about 100- I think I have a potential source some time in February. They will be small but I don't think the cats will be able to eat them or visa versa.
Janet- I haven't actually added worms to the growbeds as those fed to the fish were chopped up. I think I might just get a couple of teaspoonsful and put some in each growbed- just put them a little below the surface and let them make their own way down??? what do you suggest?
As far as the eventual eating of the cats is concern I am well aware of the potential of the barbs- I remember being spiked as a child- after that we always used pliers to hold the fish while we skinned them.
Another picture just for fun- beautiful or what??

I don't remember tandanus having any barbs, but I may be wrong...
Jim, if the SP are half the height, the tandanus may try to eat them. Depends on their size. Their not so stupid as barra to try and eat something that wont fit in their mouths but...

KP- Tandanus very definitely have barbs- one on each pectoral fin and one on the dorsal fine- and they are venomous- try not to touch or you will regret it! Not going to cause your hand to fall off but significant pain will occur- trust me - I remember!
The cats do have big mouths but overall they are still really only about 60-80mm long so provided the SP are bigger than about 30 or 40mm I reckon they will be OK.

hmmm I only ever kept them until they were too big for my tank, but used to handle them when moving from tank to tank... they were quite friendly.
Salmon cats too.

Better half has just come back from the AP system shed and reports that the tomatoes have improved significantly since she last saw them 4 or 5 days ago. I thought they were looking better but when you see something every day it is always a bit hard to notice small changes.
Looks like the added urea is having the desired effect.
On another topic I have to add about 100 litres of water every 3 or 4 days. This is probably because the growbeds are not heavily planted and I am loosing a fair bit of water to evaporation. My estimate is that at this rate I will be adding as much as 10000 litres over a year or 200% of capacity!! The top up water is rain water so I am not worried about mineral buildup.
Has anyone any estimate of how much top up water they use in their systems?

Beoootiful little whiskery things!!

For adding worms to the growbed, I just scratched a depression in the gravel until I found moisture and then placed a small glob of worms in the depression. They worked their way in to the gravel in a few minutes, and then I smoothed out the depression. Easy! (Be sure to use composting worms.)

Off to the shed now to put red tigers to work in the growbeds.
Interestingly I have read in various places that compost worms are not appreciated by fish- clearly my cats have not read the same reports.

Jim, check for leaks mate, there's no way I add that much water, and I have 10kL... What temperature is your water? What average temp are your days? How much sun do your GBs get?

KB- no sign of leaks- very easy to see if that was a problem.
Range of shed temps in the last month or so from as low as 13 degrees to as high as 31 degrees
Max water temp in the fishtank to date has been about 24 degrees with less variation than the shed. Minimum about 17 over the last month.
Lots of exposed gravel in the GBs and they are hot to touch during the warmer parts of the day.

Could you cover the exposed growbeds with something for a week to hinder evaporation and see if that reduces your losses?

Out of interest do you flood to above gravel level or just below the surface? Would that make a difference?

Trentski, the consensus is it will make a difference, and beds should be flooded to 1/2 an inch below the surface, for evaporation and to reduce algae growth. But I don't know if Jim does.

When it is not raining I am adding 200L every day or two.

My average daily usage is 30 litres/day....I do not have any leaks (check regularly)

I do have ~2,800 litres of GB media and 2,500 litres of fish water...added an AP rainwater tank which has covered all water requirements

My water usage increased as I added more GBs (and plants)

jim they are beautiful indeed!

i was only ware of the "top" spike being venemous............. for any one that cares to know hot water is a good treatment if you get stuck "as hot as you can handle" is the go. much the same for many protein based venoms and lots of marine stings.............