Backyard Aquaponics
A place to discuss aquaponics

Hey guys im wondering if there is a good guide for getting all and keeping the right balence of the nutrients and minarals you need in your AP system?

How do you guys keep the right levels of iron, mg, calcium and what als your plants need?!

I think waiting till your plants get deficiencys is a bad way of seeing what you need to ad to your system there must be a way to prevent deficiencys by keeping your minarals and nutrients on the right amounts?

Im realy thinking of just dumping some all-in-one hydroponic firtilizer in my system so im 100% my plants get what they need (dont know if this could be harmfull for my trout fish though?)


Right now iv got beans that are growing have some yellow leaves.


im also thinking of A/B testing my aqua ponic system against a hydroponic system (my mom quit the ap thing so now i have 2 IBC aquaponic systems...



Someone sent me this link which is handy about iron in AP systems:

https://www.theaquaponicsource.com/blog ... 6834e7a283

PS sry for bad spelling:)

Adding nutrients that aren't needed causes problems as well. I could see using a general purpose hydro nutrient (be careful of the nitrogen component) for a period when you have few or no fish but any other time and you'd probably be adding a lot that you don't need. Do that enough times and you've got a problem.

You could have the AP system water analyzed and get leaf tissue analysis done but that would probably cost more than most people doing Backyard Aquaponics want to spend (unless you're going commercial or already are in which case if it were me, I'd probably pay for the analysis). While you can measure the EC it probably won't have much meaning in AP because many nutrients will be bound in organic complexes.

You'd also have to consider that different plants have different requirements and solutions that would cause a deficiency in some won't cause a deficiency in others. This actually can be a good thing (see below).

Most system only need Potassium and Iron as a supplement. Occasionally you'll see magnesium or calcium needed. I don't know how many other people do this but I've found that certain plants work well as indicator plants - in particular Russian Kale shows potassium and iron deficiencies before most of the other plants I grow. Peppers and tomatoes usually are pretty good for calcium deficiencies. You may find that other plants work better than these for you.

I'm regularly adding CaCO3 (mesh bag of coral under a spigot) for pH adjustment and occasionally add potassium bicarbonate for the same reason. This generally takes care of most of the supplements my system needs except iron. Others use CaOH and KOH when doing pH adjustments for similar reasons.

Yes getting test kits and having your plants analzyed is far to expencive for the amuture AP grower.
And waiting till your plants show deficiencys is to slow, (then your aready late)
But there must be a way to calculate what your ap syteem needs.

If you have a system with 1000L water and a grow bed of lets say 1m2

What do you need to suplement on and how often?

https://www.theaquaponicsource.com/blog ... 6834e7a283

According to the artical above we would have to ad 4 teaspoons of Iron chelate (10% iron solution) every month? thats sounds like alot...

Patassium?
Magnesium?
Calcium ?

In my current system i have added Iron, magnesium and calcium but im not sure i have patassium yet. (will have to check the packaging of the stuff i added
(i added the magnesium and some more iron this weekend i dont know how long it takes to have an effect on your plants??)
But anyway my plants are having some big deficiencys ill make some fotos tonight so i can show you guys.

My PH was 6.8 on 3 june

If you see a deficiency repeat enough times you can probably anticipate it's coming back before it happens.

A lot of variables come into play. That standard was written for a system running in the tropics and probably the system was always in active growth with plant production going on. In my system I have plenty of the year where I don't grow much if anything but the fish still eat, just not as much. What happens to the accumulated iron and other micro-nutrients from the fish feed that I use from late fall to early spring ? Then too, do I get any benefit from the iron in the red lava rock I use or is that all locked up and unusable to the plants? What about the water I'm using? How much iron is in the feed I use and how much of it gets used by the fish? Does a lot of that iron get oxidized from Ferrous to Ferric Iron so that it's not available to the plants? ..... I think you get the idea.

I suppose you could use the Hanna Iron Checker to figure where your iron level is at but is it measuring available iron or all iron ? The standard method it's based on uses a very low pH so I'm betting it measures all the iron. If the number comes out low you can be pretty sure you need to add iron - marginal readings and those slightly above plant requirements are tougher because there is no indication of how much of the iron is plant available so you might end up needing to add anyway, just to be certain.

I look forward to seeing the photos. Usually when systems have a multiple deficiencies it's because they are too lightly stocked, they are using a poor quality feed that isn't designed for fish growth or they are using water that has had many of the nutrients removed (by de-ionization for example). Even a very lightly stocked system can do well once a nutrient reservoir has built up in the system but a newer system might not fair as well as an old one.

I just use tap water to fill my system (dutch tapwater no clorine ) at the moment i use this feed:

http://www.aquaponicsshop.eu/en/product ... -45mm-7kg/

A well designed, sensibly stocked Aquaponic system rarely runs into deficiencies. If an Aquaponic grower educates themselves on diagnosing the four main nutrient deficiencies systems seem to run into, ie: Iron, Potassium, Calcium and Magnesium, then identifying them early, and rectifying them quickly with fish safe products, is very simple.

Hydroponic nutrient solutions contain both Copper and Zinc... not good for fish.

There is so much B.S. on the internet about how much Iron is "required" in Aquaponic system. There is one Youtube video in particular that was responsible for that, and other “sources” then perpetuated it.

I have a single IBC system that's been running 5 years now and I've only had to add chelated Iron twice because of actual deficiency symptoms, and when I have, I've only added the equivalent of a 1/4 teaspoon of FeEDDHA per 1000L... Chlorosis gone in 3-4 days.

For the first couple of years I never even added Iron, until I grew a large Chilli plant that was holding a lot of fruit. The system developed both Iron and Calcium deficiencies at that point. I now add EDDHA chelated Iron on a regular basis, but it's only every 6-8 weeks (when I remember) and it's quite literally a pinch into 500L... and that's even with me changing out about 50-70L of water every week. My system is a display in a shop and has to look half decent, so I siphon the floor of the FT clean every week and then top-up.

This is what the plants in my system currently look like, with that tiny amount of Iron added every 6-8 weeks: https://www.facebook.com/permalink.php? ... 9392998146

That is the reson im not dumping it in my system:)

Here i got some fotos:

Well this is a tough one but I think I'm seeing a nitrogen deficiency (or excess)(Yellowing of the leaves in the squash and other plants) and a calcium deficiency (necrotic leaf margins on upper leaves for cabbage plants). The upward curling leaves might indicate a boron deficiency in the cabbage as well (I'm not sure how to handle this in AP, I probably wouldn't do anything for now (this could be normal for this plant), if you're certain it's not normal - Nate Storey suggests using a pinch of borax soap (it doesn't take much and more is not better!). That's my best guess at this point.

The only thing I noticed about your fish feed that was different is that fish meal is replaced with bone meal. That may not be a big deal, I'm not sure. The nutrients in bone meal would likely be more slowly released and the pH of the system if over 7 would cause some problems (your pH is below that now but still pretty close at 6.8 ). Bone meal is used in AP along with Blood meal as a way to carry a system through periods of light feeding (FYI - you should look at information on BSE (Bovine Spongiform Encephalopathy) before going this route if you're in an area where that could be a problem.

I have a few questions for you mostly to figure out the nitrogen situation -

How large is your system (grow bed volume and fish tank, any filtration or DWC elements and their size) and how many fish are in the system along with their approximate size?

Nitrate, nitrite and ammonia readings?

Outside Temperature and water temperature.

I'm thinking that you've had a cool period and it's caused some of the symptoms of the in ground pumpkin plant (Pumpkin plants like warmer growing conditions). I don't know if they will clear up but I doubt you'll have any further problems once the weather warms.

What I am doing:
A diverse diet for the fishes would provide most if not all the nutrients. Apart from the commercial pellets, I use black Soldier Fly Larvae in summer, meal worms, red composting worms, tubifex, gambesia mosquito fish as feed.

I also use rock dust for a complete mineral supplement and red wriggler worms in my grow beds mineralise these. Also between 300 g to 1 kg spent coffee grounds to each -IBC cut- grow beds.

I have grown tomato with the above setup and brix measurement was 11.5 (almost excellent), the taste and aroma of the tomato was out of this world. It was like sprinkled with sugar.

What I want to do:
3 minerals that are always problematic are calcium, potassium and iron. These are the common deficiencies according to Dr Rakocy and Dr. Lenard and I don’t want to add unnatural chemicals like calcium hydroxide, potassium hydroxide because IMHO this is not different than running hydroponics.

I am planning to have a little worm composting in the grow beds. A 150mm pipe with a lid would do on the corner of each grow bed. These worm composting little towers will be specially fed.
For Iron, couple of rusty -mostly iron- nails, silver beet, spinach in the compost towers
For potassium, feed the worms with sweet potato, radish leaves, banana peel, carrot, soy beans and charred orange peels.
For Calcium, feed the worms with almond meal, cabbage leaves and crushed –almost dust- egg shells.

I am guessing, this method would solve most deficiency problems.

Gil Carrandang’s Cal-Phos recipe may also be used as a foliar spray (Google it)

I started using Maxicrop to supplement trace minerals based on some reading in this forum. It seems to have had a positive effect, although I was not having very serious issues to begin with. I am still working out my dosing, but it does not take much. This has a lot of nutrients, however, so if you are only short in a few areas, you may end up with a problematic overabundance of certain nutrients as initially indicated by scotty435. I don't know that a seaweed supplement like maxicrop is the answer for you, but it is certainly worth investigating.
Here are three threads in this forum that discuss the use of maxicrop:

http://backyardaquaponics.com/forum/vie ... f=1&t=9797
viewtopic.php?f=14&t=19456
viewtopic.php?f=11&t=26889

I use a spray bottle and foliar fed my cucumbers twice weekly with hydroponic fertiliser from my hydro solution tank .
This seemed to work well in terms of yield from the cucumbers ( we got plenty of cucumbers ) and didn't seem to adversely affect the fish .

I just dip the bottle into the hydroponics tank until full and then spray it all over the plants , top and bottom of the leaves .

A big thing to remember is every system will be different and not one rule works across the board. So many factors.

Some may find they never have to make additions and then some need to fight the system its whole life, Ive seen both sides of the story over and over. I personally only added a few spoonfuls of iron chelate here and there in the 4 years my system was running.

Make good choices from the beginning like good media, good quality feed and well designed system. And be cautious with over-filtering the system. Im still a firm believer that letting some wastes mineralise in the media bed is the foundation of a healthy back yard system. Or if you are pre-filtering then make sure you mineralise those wastes and return the nutrient rich solution back to the system otherwise you will find you are constantly adding those missing nutrients.

Ive also found over the years that often you can have sick plants from the start, whether you have bought them as seedlings or germinated from poor seeds. Ive pulled out numerous plants in the past simply because they were no good and struggled. Or it sometimes may be that your system cannot grow some plants for unknown reasons. I could never seem to grow basil but yet I could grow it in the garden? Never worked that one out. Thats actually how Dasboots system thread name came about haha.

And as mentioned, learn the signs of deficiencies or just simply post a pic here and you will generally be answered within a few hours by someone with more experience. Easy peezy.

... ... ...

You can't do that!... ...Have u not read the Aquaponics rule book Charlie?...

Your fish will go blind, get gill disease and die within months... and your plants will get root rot and die!... and your chooks will turn into emus and kick your outhouse down!

Haha, yea imagine the chaos, what was I thinking. Maybe adding 36 RFF's, 94 MBBR's, 4 drum filters, 20L of snake oil and a bag of onions is a safer way to go. My bad.