Backyard Aquaponics
A place to discuss aquaponics

Hello,
Can anyone give me some feedback on the deficiencies in the pictures below?

The big Kale and Cauliflower plants have haltered their growth 3weeks ago. What does the coloring of the leaves indicate? I’m thinking to remove the plants this week since I don’t expect them to suddenly start growing again….
The small lettuce and Chinese cabbages are planted about 1,5-2weeks ago and are growing ok, but still couring doesn’t seem good

I’ve added:
IRON CHELATE (15theespoons 3 times over last 5 weeks) and POTTASIUM SULPHATE (10 theespoons 3 times over last 5 weeks)

Another question: Is there an overview (with pictures) available with deficiencies and remedies? I’m writing an Aquaponics guide for the project (eight Ethiopian farmers to start with) and I’m in need of such a thing.

I think you have more than one thing going on. Looks like you have one or more nutrient deficiencies they are from a mobile nutrient. A shortage of one of the mobile nutrients usually shows up in the lower leaves first. You're seeing that in the red kale leaves (also the ones with light areas between the veins) and the yellow lettuce leaves.

The reddish lower leaves on the Kale may indicate a Phosphorus deficiency. Phosphorus is used in energy transport within the plant. Shortages can cause stunting.

The yellow lower leaves on the lettuce look more like nitrogen deficiency. If the yellow leaves were on the top part of the plant it would likely be an iron deficiency but they aren't. If the lower leaves yellowed more in between the veins like on the kale and died along the tips and edges then it could have been potassium (might still be). Magnesium looks similar to potassium but usually the veins are a darker green.

If you correct the deficiencies soon, the plants will probably recover (you'll probably lose some of the lower leaves though). Since you're seeing a couple of deficiencies it's possible that the nutrient levels are pretty low or you've been adding too much of something else which sometimes causes uptake problems because of competition between nutrients. I don't know what is available in your area. It would be a turn off to some but human urine (from a healthy person who is not on any meds or drugs) has most of the nutrients but it can put too much ammonia in the system so you need to be careful if you try this. The ammonia is a break down product so it won't appear immediately.

Other possible sources are a combination of blood and bone meal (in most systems, this is sprinkled on the grow beds, I'm not sure how you'd do this with your setup). Compost Tea might be another possibility. I'm sure others will have additional suggestions and maybe a different take on what the deficiencies are.

This is the guide I use (below)

Deficiencies are complicated too much of one will tie up others as Scotty said.

A good start guide might be (1 unit of potassium 3 calcium 1 magnesium) with a foliar iron as needed

Good quality fish feed is essential if you want to avoid supplements

http://www.harvesttotable.com/2009/05/s ... deficienc/

One thing i noticed is there doesnt seem to be much of a root system on any of the plants....

I can probably get some Phosphorus source from a nearby Lilly farm (I'll check). I think that by increasing the feed amount I will have solved the nitrogen shortage (I've recently planted a lot whitout increasing the supply of fishfood)

Should I try to get Calcium and magnesium as well? (I will become like a hydroponics system, but I do need to have the system running fine to set a good example to our students)

I agree with the nitrogen.
Also the coles are a bit sensitive to light so make sure they are getting adequate light. (broccoli seems slightly leggy to me)

lastly, all three are cool weather crops. Make sure you are not having an overheating issue.

If you've increased the feed your phosphorus and nitrogen levels will pick up and shouldn't be a problem. If it continues to get worse then your system is out of balance and you'll need to add something more. About how many grams of feed are you giving your fish each day. How much raft area do you have?

Poppa brings up an interesting point about the heat and these plants - even though you're probably headed into your cool season. It looks like you're only getting up around 81 F (27 C) during the day so I think you're still OK but if it's been hotter, temp can have an affect on nutrient uptake so that may be part of the problem. Is this setup inside a greenhouse?

27C is max temp in daytime. But in the greenhouse it does get warmer.

I'm currently feeding 400-500gram a day for 16.3kg of fish and an grow area of 11m2 (2 weeks old plants) in the DWC and 4m2 in the Growbeds (RedAsh). But I've increase this to 800gram.

I've also discussed with dlf_Perth to raise the planting cups to create an airzome between the cup and the DWC. Since we do not use aerators in the DWC.

I've got a offer from a commercial farmer to buy some supplies at factory price. I want to have just a little of everything in supply that might be needed in Aquaponics. What do you recommend:


Amonium Sulphate CZAV NH3SO4 21%N + 60%SO3
Bone mill National Fertilizer Manuf. Company organic 1%N + 23%P2O5
Borax ETI Mader Na2B4O7.10H2O

Calcium Nitrate (calcinit) Yara Live CaNO3 14.4%NO3+ 1.1%NH4 + 26.5%CaO
Calcium Nitrate (tropicote) Yara Live CaNO3 15.5%NO3+ 1.1%NH4 + 26.3%CaO
Copper Sulphate Joint stock CuSO4.5H2O 25% Cu

Dolokal Supra Sibelco CaCO3 80% CaCo3 + 19% MgoCO3
Fe - EDDHA Ciba, Horticoop Fe chelate 6% Fe
FE-EDDHSA Horticoop Fe chelate 3% F

Kieserit Agrifirm MgSO4.7H2O 25%MgO + 50%SO3
Magnesium Sulphate Cebeco, Horticoop MgSO4.7H2O 16% MgO + 32% SO3
Magnisal (magnesium nitrate) Haifa MgNO3 11%NO3 + 16% MgO

Manganese Sulphate Norkem MnSO4 32%Mn
Multi -MAP Haifa NH4.H2PO4 12%NH4+ 61%H2PO4
Multicote Haifa NPK+MgO4 15% N, 7% P, 15% K+2MgO

Nitric Acid Horticoop H2NO3 68% acid
Patentkali CZAV K2SO +MgO4 30% K2O + 10% MgO
Potassium Nitrate Kemapco KNO3 13%N + 46% K2O

Potassium phosphite Biron K3PO3 20% K2O + 30% P2O5
Potassium Sulphate K2O S03 50% k2O + 45% SO3
SOMO(Sodium molybdate) Cebeco mestoffen BV Na4MoO4.2H2O 19% Na + 39%Mo

Urea Sabic (NH2)2CO 46%N
Zink Sulphate Grillo ZnSO4 23.6% Zn

Raising the cups that hold the plants sound like a good idea. The feed levels are about in line provided your filtration is done right. I'll have to look through your other thread and see if you've already described this.

I'm not sure what to tell you on the list - I know that the ones below can be used for AP. Some of the others on your list can also be used but usually aren't (like potassium nitrate, potassium sulphate, calcium nitrate and calcium sulphate). Normally we would use Potassium carbonate (wood ash) and Calcium carbonate. Potassium phosphite is a fungicide. I would avoid the zinc and copper compounds since fish are sensitive to these. Manganese compounds, you won't need. Same for molybdenum. Since the pH usually falls over time adjusting the pH down is usually only done when starting a system (most systems don't need adjusting). You also have some general fertilizers on the list that wouldn't normally get used but might work for keeping a system going if you can't find something better.

Bone mill National Fertilizer Manuf. Company organic 1%N + 23%P2O5 phosphorus

Dolokal Supra Sibelco CaCO3 80% CaCo3 + 19% MgoCO3 Maybe - would be for pH and calcium
Fe - EDDHA Ciba, Horticoop Fe chelate 6% Fe MAYBE - for iron deficiencies if you can't find Fe-DTPA

Magnesium Sulphate Cebeco, Horticoop MgSO4.7H2O 16% MgO + 32% SO3 YES for magnesium deficiencies

Bone meal can provide nitrogen and phosphorus which might be needed.

The iron chelate Fe-EDDHA (Fe - EDDHA Ciba, Horticoop Fe chelate 6% Fe) turns the water red making it almost impossible to read results from testing the water. It would help with iron deficiencies though - FeDTPA might be a better choice but if the EDDHA is all you can find then you probably should get some.

Magnesium Sulphate - Magnesium Sulphate Cebeco, Horticoop MgSO4.7H2O 16% MgO + 32% SO3. This is the same as what we call Epsom Salts. This would be good to have if you run into a magnesium deficiency.

Thanks Scotty435, this is very helpfull, I will just make sure we have a little supply on these. Since the opportunity to buy from this farmer might disappear soon it would be good to have some in stock, just in case.

I should mention on the general fertilizers that they may provide nitrogen in different forms. Ammonia in too high of quantities could kill your fish. On the other hand if the nitrogen is provided as nitrate the Ammonia and nitrite oxidizing bacteria won't be able to use this for energy. Organic fertilizers like blood and bone give you a bit of everything and keep the cycle going.