You guys thought I was a slacker just resting didn't you. Well I'm not. I bought a house, and I've been working away at my 2nd aquaponics system. I've written up a bit about it on my homepage, aimed at people who don't know anything about aquaponics:

http://athoughtadrift.com/gemmell/2008/ ... e-mark-ii/

Rather than posting all the same info here, I'd rather you just clicked the link above, theres no ads or any other nasties .

I do have some specific questions though.

My system is running on a timer, and holds 4 uncoloured goldfish. The water is a funny colour:



I am worried that it is more of the "cloudy white, algae badness" colour more than the green pea soup colour that is generally accepted as being OK. I have done a 100% water change, and the water is returning to this dirty colour. Any ideas? Could just be scoria dust, but it's not settling out very quickly.

Everything is measuring 0 (or close to zero) at the moment as I don't have enough fish to really start things going.

Anyway, feel free to pick apart my system.

Hi Simon,
looks like the scoria dust. maybe put the sock back on the pump outlet for a while

Looks good gemmel, I think if it was my system I would be adding a filter somewhere for a couple of days to see if the water will clear a little bit.
When i fully started mine i had old socks (and still do)covering the return pipes to catch the bulk of the pvc shavings and heavier dirt particals.

With floating stuff try to get a circular clarifier fitted in somewhere.
A bucket would work fine at the return in FT, drill inlet at 2/3 of hight, tangential current, water outflow through hole on the top side of the bucket. Usually takes 80 % of stuff floating out, depends on water speed and size of particles.

I've gone the sock option for the moment, though the "circular clarifier" bucket concept makes sense also. I did have a pair of stockings over it previously and it did a fairly good job, but I changed to a cowel ... because I had one.

Will get some more photos and hopefully fish this week.

Update: New photos up on the blog site with some basic info.

I had 70 fish delivered on Friday. They only just made it. They were sent Thursday morning, and by 6pm Friday evening they hadn't arrived. They turned up at 6:30pm, and the guy apparently mumbled something about them being given "to the wrong driver" - lucky someone was still at work to take them or they would have died over the weekend!

So I have 74 gold fish of different varieties. They have been in there over the weekend and it's all going pretty well. No casualties.

Metrics:
28/3 (day of fish delivery) 22:00
PH 7.2
NH3 0
Temp 14.5

29/3 13:46
PH 7.2
Ammonia >0 <0.25 (greater than zero but less than 0.25, could be me dreaming)
Nitrite 0
Nitrate 0
Hardness 70 (thats pretty darn soft...)
Temp 13.7

30/3 08:20
Ammonia 0.25
Nitrite 0
Temp 12.5

30/3 18:00
Ammonia 0.25
Nitrite 0
Nitrate 0
Ph 7.2
Temp 15.7

I don't know whether i'm reading the Ammonia test right though, whats it look like to you guys/gals? 0.25 or is that wishful thinking?

looks to me like you haven't added the second bottle of drops. normally the colours are very distinct, maybe a pic with the test tube up against the shit background.

Take it as a 0.25 (I do)

Definatley added the 2nd bottle of drops. I always have trouble telling, even with the first system.

With 74 small goldfish in a 1000L system, feeding a pinch of koi food twice a day, I thought ammonia would shoot up.... but it just seems to be creeping up. I'll measure again tonight.

74 goldfish in 1000L is 1 fish per 12L, which is a pretty low stocking density if the fish are small. I had my original system that low and i never even saw ammonia.

Well I worked out why I couldn't see much in the way of Ammonia. Seems to be converting to Nitrates! Woot!

I had been running the system with 4 uncoloured goldfish for about a month, but never had anything register on the tests. I guess the bacteria was already there and working, but with minimal Ammonia. So once I chucked in 70 extra fish it just scaled up pretty quickly. I have never measured any Nitrites.

Below is my pic of the Ammonia, Nitrites and Nitrates (respectively)


Temperature 16.2 degrees.

Got to be lucky some of the time Gemmel.... nice to see you back up and running....

Still going well.

Ammonia 0
Nitrites 0
Nitrates 5
Ph 7.2
Temp 14.4

(Pictures, we love pictures)

Ammonia, Nitrites, Nitrates respectively


Ph


Fish


I forgot to feed them this morn. Looks like they took it out on this little guy. I've entitled this picture "Look ma, no tail!" Watching him swim is funny.


Some weak ol' lettuce seedlings

It is bacteria not fish attack (fin rot) if i see well on the pic.
Treat with salt quick before it goes further.
Nice system by the way

nice setup mate. Just clip an inch or so off the hose washing onto ur lettuce, it may rot the lettuce otherwise. Ur nitrates may climb til ur plants get a little more established. I managed to fit 10 brassics per bathtub, one tub broccoli, one savoy cabbage, one cauli. They will be ready 10-12 weeks after you put the seedlings in. (One of my cauli leaves is nearly a metre long and 30cm in diameter!)