Backyard Aquaponics
A place to discuss aquaponics

You need to remember that pH has a major affect on trace element uptake... many of the people that experience deficiencies are running systems with pH around 8.0-8.5..

Hrm... so what kind of nutes are we talking?

I'm worried about adding things and what it might do to my yabbies They are going along well... with a bunch of them in berry.

Imy what everyone is telling you can get confusing...

Regarding nutrients: Do some research on what vegetables require. Basically there are 2 groups. Macronutrients like nitrogen, phosphorus, and potassium. The second group is micronutrients. These are things like trace elements and minerals: iron, magnesium, calcium, etc, I think there's like 20 of them. you need to figure what your specific needs are by what you are growing.

here's the deal: fish food (the only nutrient entering the system) is heavy in nitrogen and usually very little of everything else. You need to supplement the minerals and elements, especially of you have fruiting plants like your tomatoes. Seasol I heard from ozzie is super good, he turned me onto maxicrop which is working great for us. As for it being harmful to yabbies I don't know fer sure, I know its harmless to my fish. I would suggest trying to add a couple of ounces to your water as see. A little goes a long way for the veggies and won't harm your fish. I was scared too but after some experiments I've added all kinds of stuff to my water and the fish have been OK.

Rupe's point is if your pH is too far from 7, like 8 to 8.5 then it doesn't matter if all the nutrients and minerals are present, the plants cannot absorb them. So you need to monitor that. I had that problem too.

I guess what everyone is telling you is that unless to supplement some of your nutrients, you're not going to get good growth, I am living proof of that. Have some faith and learn from what other have already done.

Hope that helps

Thanks goes to rupe for the maxicrop tip

Nothing difficult about it at all.

Ph from 6.5 to 7.5, add some seasol + fish = awesome growth.

I didnt use seasol for the first 4 months or so, lettuce grew, silverbeet sort of grew, tomatos got little fruit, same with cucumbers, celery was stunted.....added seasol and *boom*

I see.

I've added some coral skeletons (well, dead coral rock) from my marine fish tank because I knew the yabbies would be needing some calcium of some kind in there for their shells. I did this when the yabbies first went in.

I also stuck some goldfish in there and feed them daily (probably over feed but I guess the yabbies pick up whatever the fish aren't into)

The tomatoes are probably growing between 1/4 to 1/2 an inch daily at the moment which I was happy with.

What dosage of seasol are we talking to be ample for my little system?

I think, including the grow beds, its around 1000l.

There is two methods, depending on how clear you want the water.

250ml, one cup all at once per month,

or 1/4 cup per week per 1000l.

Once you get some good cropping, cease the seasol until you start to notice stunted growth / small fruit, then dose again.

My 8000l system gets two litres of seasol per month or so, 1 litre one day, then the other the next. If I had more fish I would probably require less seasol.

Your tomatoes will grow well, but you may or may not have problems with fruiting - so much of how a system performs depends on the type and blend of gravel that you use, and the amount of nutrients that it holds.

Thanks for that.

I also have an update on the yabbies and fish. All the 5 goldies are still alive and fat little things (no surprises there)

We're down to 27 yabbies all up (purchased 40, lost a few in the box, a few cycling and recently 3 with in-house fighting and breeding)

We have 5 females in berry. Today we took all the yabbies out, rearranged the pipes and put the females with eggs in milk crates covered in shade cloth then dropped in the tank. We already have 2 eggy females in a 100l drum which leads to the main tank.

We've been talking and think we will get another trough to replace the 100l drum. It will be gravity fed from the grow beds then overflow to the tank we already have sunk into the ground.

This way, we'll have a tank for adults (and goldies) and one up top to put the females when they have eggs. We'll then remove the females and let the little ones grow out in the top tank. Beats messing with milk crates and will hopefully mean more stock and nutes.

Now to get on eBay and check out tanks

A small problem yesterday. One of the pipes clogged over night so more than half the tank emptied onto the ground. There was just enough water left in the tank to cover the PVC pipes for the yabbies. The goldies were looking a bit desperate.

Luckily we had a little rain water in a drum so we topped it up. Its still not full to the top but we're hoping for more rain. Forced water change I guess

I THINK everyone is still alive. Even the goldies.

Small Pipe?

Nah, I stupidly put a piece of fly screen on the 'nursery' tank outlet to stop babies flowing through to the main tank with the goldies to gobble them up... problem is, the warmer weather caused a little algae bloom and it clogged. Some of the water was still getting through (hence not emptying the whole tank) but it was cloggy enough!

Woops

I have emptied my 8000l system to about 2000l once - hydroton stuck in a siphon for a whole day

I got a tomato, I got a tomato! You can't see it, its pretty much a green dot above the flower... but its a tomato!

They don't look as bushy in the photos as in real life. Oh well.

Yabby babies! How exciting!

Any ideas on how long the mum should stay in with them so she doesn't eat them?

I pulled mine out within a few days... just in case ...

Thanks. I think I will too. Its been cold weather and thy are coming out of their eggs over a couple of days. I think they might breed again if the weather warms up. I'm looking for another tank right now