Backyard Aquaponics
A place to discuss aquaponics

Hi James , You're starting your grand adventure with aquaponics. Many of us guys have been growing fish in one form or another for years and done all the small and on the cheap, behind the missus back , crashing and burning etc in the privacy of our own home - or for some of us we did it before the internet existed when the opportunity to share our "work" with everyone did not exist.

I can remember getting neon tetras for my aquarium and staying up all night because I thought one was sick . Now if it looks sick it is euthanized and off to the shop for another (the kids will never know).

To be honest you often learn more by making mistakes than getting it right and certainly if you make a heap of mistakes to start off with then you are better able to deal with HSM. It's all part of learning.

It took me 3 years to convince the missus to let me spend the money on the fish . In the mean time I built her a deck and put a pool in - then it was my turn!

Hi it's been over two weeks since you last posted. How is your system and how are your fish going?

Hi James,
I've been flat out with work and have not had much of a chance to post.

Fish are doing well. The weather has been very cool for us but heaps of rain, so I cant complain. The tank is up to over 20c and the fish have nearly doubled in size. They still wont feed on the floating pellets and I have to soak them for a while and then squeeze them so they sink. Once on the bottom they attack with gusto.

The plants have gone mad and growing well. Like you I have a bit of an aphid problem at the moment but a squirt with the hose soon dislodges them. The ants are moving them around so I put some ant baits out to sort them out.

It is fairly clear that some plants do better than others so I'm keeping some records and it proves to be consistent then will concentrate on the easier to grow vegies. This may be a problem when I get to 6 beds and mostly beetroot!

I'm hoping to get some time off work so I can get the next 2 beds and 1000l tank in.

How is your system going?
Cheers
Marc

Hi Marc,

Just read your system thread. Don't know how I missed it.

Very nice, well thought out system. I like your backup system.

Thanks Arbe,
The backup system has worked 3 times so far in the short time it has been going! It has to be the must have item after filtration and fish.

My system is growing fantastic. The wife is getting very interested because the plants look so happy. I have planted a rhubarb that was not growing well in the dirt into the system two weeks ago, it has two new leaves and sucker growing already, the tomatos plants look so strong . I am still fish less, using pee and seasol to grow with.
my tank size is to small to maintain constant temperature and I will be moving soon so I will not buy fish. It has been a great learning experience.

Well show us the pics then...

How are the frogs going around your system. Or have your fish eaten them?

The frogs are still breeding like mad. There must be over a dozen of them which is interesting as we are a long way from free water and these must have come from the tadpoles my wife and kids brought back many years ago and have survived and possibly bred in the green house (there is a little free water in there) but never seen tadpoles. Anyhow the fish ate 90+% of the tadpoles when they were little (both SP and tadpoles) but now I have maybe 15 that have survived to the point that the fish leave them alone - I think . There is one with half a tail.

The frogs are safe with the SP as the frogs are 10 - 15cm long bodies so are safe from them. Wait 'til the trout arrive in the autumn.

When it is wet the frogs move in and out of my green house. As there are 4 sections (3 between the fish and the outside) the trip outside is long (for a frog). When I go in at night there are often frogs on the path. As soon as they see you they stop moving but when you shine the torch on them they have moved. Its a bit like the Dr Who episodes with the statues that only move when you are not looking at them

Hi all, it's been a while since I have provided an update on my system.
My last post was about the tadpoles, little did I know that they would turn into a saga. The buggers just grew and grew and rapidly over took the SP for size. When it came to feeding they hogged all the food and I needed to adjust my feeding so the fish got some.

The tadpoles grew to about 4 to 5 inches long. I have never seen a tadpole that size before. I assume tadpoles are largely vegetarian so they just bulked up on the high protein diet I was feeding them. The muscles on the tails grew so large the tails ended up distorted and frequently bent into an S shape - they looked like body builders!!



Check out the size of the muscle in the tail - this is a normal one!!

What was funny was that when they fed they had to come up for air. So they made a bee line for the surface and popped out (often 50% of their bodies came out) grabbed a breath and headed back down for some more food. Now imagine someone with their face only inches from the water's surface and a taddie surfaces like a breaching submarine and you have some funny moments.

Anyhow all the high protein food can't have been good for the poor little guys as they ended up having trouble swimming and staying orientated in the water. As they started to develop legs they started to die and I spent every morning fishing them out. Other tadpoles growing in the same location (my duckweed trays/tanks) were all ok - but then they were not fed.

as they developed into frogs they continued to die, and I continued to fish out the dead froglets. Often the fully formed frog would be found belly up on the bottom of the tank. When you pull them out they are sometimes still alive and seem to have drowned/in the process of drowning.

Even worse is the odd leg and bits of tails that were missing as the SP got bigger and gamer and did a little snacking.



This tadpole has part of its leg missing (assume a SP was snacking). I rescued (seemed to be drowning on the bottom of the tank) a froglet with the same leg and part of the leg missing - so I assume it was the same as the tadpole in the picture. It is now (at least was) living happily in another part of the greenhouse
Of about 50 odd tadpoles that made it past the first few weeks of hatching (the SP ate most of the hatched tadpoles) about 10 or so made it to fully formed frogs - and big as well - about 1.5 to 2 inches long in the body. Now they have to survive the older frogs that will see them as a convenient meal.

Life is tough in the pond.

Now that I have the tadpoles out of the way it's back to the fish.

Firstly I have a confession to make. I started out with 100 SP - 25 were to go to some friends. I only had 2 beds so I was overstocked but had every intention of putting in the extra bed or 2 ASAP. The best laid plans... as they say. Well work took off and the friends did not take the fish and I was in no position to put 2 extra beds in. So I added 2 extra drain holes to the inner standpipe and changed the pump cycle to 15 mins on and 15 mins off. It drained perfectly with the extra holes in the 15 mins. My theory was that if I increased the water throughput I would increase the filtration and buy me some time until I could get the 2 or 3 extra beds in by Christmas.

I tested every second day and the ammonia never moved off the bottom (somewhere between 0 and 0.25), even with the odd dead tadpole or frog I did not find in time!! So far not one fish has died.

We have lost power several times including one time when it was off for over a day (lightning struck a tree over the road and one at the back of our place). The backup system worked perfectly. (Can't say the same for a fair few of our electrical gear in the house)

The temps in the green house have been up in the high 30s every day but the tank water rarely goes above 25C - even with blowing air into the tank from up near the top of the green house roof where it is 45+C and no air at night. I'm thinking I may be able to keep trout all year round if this is the same next year.

Feeding has been interesting. I'm using far less feed than I expected. Rupert and others have suggested that young SP will eat around 5% of their body weight. With the fish sizes ranging from 125mm to 225mm I would guess that the average weight would be around 50g. This would mean that there would be about 5kg of fish in the tank and should be eating (at 5% of body weight) around 250kg per day!! I would be lucky if the fish ate 50gm of food per day and most days it would only be about 30gms. Even if I got the weights way wrong that is still a big difference.
Any suggestions why they would not be eating as much as they should be?
perhaps the lower food that they are eating is contributing to the success of 2 beds and 100 SP.

Anyhow here are some recent pics I took around Christmas

250 grams I think you mean
I don't know anything specific about SP, but I know that tilapia don't eat much below a certain temperature.
Maybe your temp is too low for the SP?
Just a guess.

Thanks DuiNui, ya dead right it should have been 250 gms!!

the temps are between 22C and 25C, so should be spot on for SP.

Marc, your % daily feed ration varies according to fish size, water temp... and fish behaviour...

Your fish should probably be closer to a 2% feed rate...

The chart I usually reference... is an "optimal" feeding strategy... always be guided by your fish feeding response...

Temperature, and barometric pressure will influence your Silver Perch feed response almost daily... sometimes even within a day, particularly with pressure...

Here's the chart again...

P.S ... based on the "length" of your fish... they would probably range from about 60gm - 200gm...