Backyard Aquaponics
A place to discuss aquaponics

Aahhh, found the article about fe edta, dtpa bioavailability based upon pH.

For the graph showing the ratio of Fe availability compared to the pH.
http://edis.ifas.ufl.edu/LyraEDISServle ... _version=1

For the full article, pls refer to :
http://edis.ifas.ufl.edu/hs1208

There are others, but this one seemed more 'scholarly to me'.

That's why at ph 7+ (in my system), using Fe EDTA *supposedly has minimal effect*, thus I 'temporarily' tried to lower pH down below 7.

Got some insulation and wrapped it around the tank. (note : not sure if it also helps, but cut up other spare pieces and placed it inside the gaps of the IBC frame as well - additional insulation won't hurt I guess).



I'll try to bump up the temperature with a 300W heater during the morning and see how the SP fry respond in the Sump Tank.

Fish Tank with the trout will just get the benefit of warmer water circulating through.

Not sure how to insulate the IBC cut down Grow Beds tho.. anyone with ideas?
I'm thinking the sides aren't a problem, but the bottom of the GBs are inaccessible, and are resting on metal bases. The top media could be covered with straw/hay/mulch type material, so long as it doesn't decay too much. Would that cover encourage mould/other undesirables?

TIA.

What sort of insulation is it?

jayendra,

it's about 4-5mm thick, reflective silver one side, and white on the other, with a compressed insulation sandwich.
used for attic wall insulation I think.

Tried out the 300W heater during a sunny day when the solar panels were buzzing at the inverter.
After 6 hrs of it sitting in the sump tank, I noted that there wasn't any real change in temps. Both tanks were insulated on sides, but tops were open and GBs were also exposed. Realistically, a 300W heater isn't going to do squat with 1500+L of water in a 10-21C max day.

The only reasonably practical solution for me is to move those silver perch fry into their own separate system for indoor heating.

Thought it was safe to extend my test readings intervals. Today, did the test, and find a huge spike in nitrates.



At least there's lots of goodies for the veges.

Hello aquanoob

I have heard that water heater work better when they heat a small body of water which than gets cycled into a larger body of water.

Like your work with the paint on the cages, looks professional.

Cheers

With your growbeds insulation - you could try some mass around it like cement sheeting layers or bricks etc.
Something to catch the warmth of the day. Water is a good heat retainer.

Looking good on the Nitrates

Thanks Gwydion. Painting them was enough to avoid having to build a screen to the house

As for the GB insulation, as they're raised, I'd have to use sheeting (not brick), but as the surface of the GBs are huge heat sinks themselves, I've gone and tried out with chicken wire over the GB to help reduce frost and contact wrap (lol) film over the wire. Wire was free, and the better half wouldn't miss about 4m of contact film from the kitchen

I've only done it with one GB, and seems to have made a positive difference. May do the same with the other GB too later this week if temps are expected to go below 5C overnight.

As for the growth, the Pak Choi has been great, and harvested the outer leaves twice already, and transplanted the new shoots to other GBs. Also took out some of the lettuces and put in Taiwan white cabbage *I think* - they're the ones with the light coloured leaves.



Peas are doing well, but I will remove/transplant them to the soil shortly, as I'm too lazy to shell them (been eating them out of the pods raw instead), so they never make it to the kitchen. Coriander must be loving the high nitrates, finally growing fast.

Tomato plants are doing super, but capsicum, chilli and basil are struggling - hence some chicken wire/cling wrap as a test measure

Yep, thats what Ive done. In a 150L aquarium. 300W heater.

OK, picked some more from the GB. Pak Choy is great for just picking the bigger leaves and leaving the plant to sprout more. However, doesn't look like you can keep doing it forever, will need to uproot them and put in new ones, I can just imagine the size of their roots by now. Threw in a sprig of mint to get it established a bit before pulling it out and planting it elsewhere.


Maybe putting coriander into the system wasn't required, as I've figured out we don't use all that much, may need to transplant into the proposed wicking bed/general garden bed area. Either way, lots of greens for the table now


And for those leaves that didn't cut it, they'll go into the fish tank to see if the SP fry will nibble on them. I used scissors to shred the leaves a bit before dumping the whole leaf in.


Point to note, lucky I checked the GB, one taiwan lettuce plant was totally infested with aphids , pulled it out and threw it away, and inspected the nearby plants to check further.

Hmm, lost a Silver Perch fingerling recently. Noticed the trout were off their feed, and then did tests of the water.
Master Test Kit results:
Ammonia was at 1+ppm - green *bugger*.
pH is 6.0 or lower!
Nitrates are high *Red*.
Nitrite is zero.

Checked the pump and noticed a half decayed SP stuck against the shade cloth mesh around the pump.
Removed, and next day did a small (15%) water change.
I threw in some *more* crushed shells into the sump tank.
I also added a cupful or two of salt to help.

Found 3 other SP fingerlings in the shade cloth, and transferred to the garage aquarium.
Noticed that the SP in the aquarium are definitely bigger by half to double those from the sump tank.

Will monitor further to see if the ammonia will drop off soon. Might do another water change tomorrow pending test results.

Was going to do a general clean up after the recent rains and found a dead drifter in the FT today. Fished it out, and the other fish looked OK in the tank. I'm not sure what could be wrong with it. It was drifting at the bottom of the FT, near the SLO with tail elevated.

Checked it out, the skin looks fine, no blemishes/skin diseases. Eyes didn't look cloudy, and looked in generally good shape.







Not sure what killed it. Gutted it and looked pretty 'fresh'. Wrapped in gladwrap and chucked into the freezer. 250mm at 247gms weight.

Wish I could have found what what it died of.

Q: anyone would NOT think it safe to eat? and no, i'm not asking for legal opinions

Hiya, the eyes look clear cant have been long dead.
It looks like like it may have had frypan disease.
I'd eat it. In fact I'd have eaten it already.
Can't beat fresh fish.

Lack of air maybe? Are the others feeding ok?