Backyard Aquaponics
A place to discuss aquaponics

My trout this year have failed to thrive so instead of coming home to them floating on a hot day, I have decided to set up a small system in a spare room and hope that I can grow them beyond the 200-250 gms they are now.

I purchased them in April and they seemed to feed and grow normally. As the months went on they became fussier, might only feed once a day and often left food floating. I could easily put them off eating by opening the tank lid for too long, adding water or looking at them the wrong way! I have had trouble with low pH – my system is on rainwater until summer when I top up with dam water. My plant growth has also been poor which maybe from the pH – although I haven’t had any nitrates for over 12 months so I have added Seasol occasionally, iron chelate and Eco Fungicide to help mitigate plant problems.

I have been running approx. 30 x 2 yr old Silver Perch and 40 x small Murray Cod in one tank and 30 Trout in the ST.
Water chemistry is stable at pH <6, Amm <.25, Nitrites & Nitrates 0, salt approx. 2ppt
My outdoor system is made up of
1x 1000ltr IBC FT
1x 1000ltr IBC ST
8 x GB bath tubs (vol 275ltrs each = 2200l tot) (surface area 5.5m tot) (media depth 350mm)
GBs drain to FT
90mm SLO from FT to ST
7000l pump in ST to GBs
Solar back-up system & solar heating

My indoor system is made up of
1 x 700 ltr FT
1 x GB Bath tub
Constant flood
Pump – to be decided on – 750GPH (2800l) Rule bilge pump or 6000l pump (I have both of these not being used at the moment)….I probably need something in between.
I will need to purchase grow lights as this is my first foray into indoor growing & I am looking at sticking with Asian greens & lettuces.
Any ideas on the grow lights would be great.

The tank is now full with water from the outdoor system and I used a few buckets of media from 1 of the growbeds too. I will set the pump up on the weekend and get the water circulating – I don’t suppose it will take long for the bacteria to establish.

Fingers crossed I can grow the trout to a decent size over summer in a cooler environment & if it is successful, I could always bring the Silvers inside over winter.

nice tubs, not sure what would be upsetting your trout?

have tried raising the pH with anything? less than 6 is not a good thing.

The indoor system.

Hi Slowboat,
I have used brickies lime and I have shell grit in the beds as well. I can bring it up to 6.4 - 6.6 & within a few days the test kit is all yellow. I have to put in a few table spoons of the lime for a change to register.

Where did you get all the tubs from? they look newish.

The nitrification process makes the system acidic but the lime should correct it easily.

sorry I don't know why your water is so acidic might something to do with Carbonate Hardness?

Hi team41,

have you been keeping track of your water temps, and what air are you giving them trout need lots more than natives.?

If natives fish are doing well and the trout are not my first things to look at would be the (above) water conditions. It may be outside of their comfort zone so they go off food and don't grow.

Hope this can help and God bless, froggo

Hi Froggo,
I am running a 35lph air pump with 4 airstones & I have had a second pump running for weels just splashing water back into the trout tank - I don't think I can do much more in that regard.
Temps were nice & low during winter & have warmed up now. Today's reading was 18.5c - ideal for trout.
This is the 3rd batch I have had & the least successful - I am still leaning to the pH factor.

Slowboat,
the baths were all new from some display homes which had a change of mind & have been sitting around here for years (along with loads of other stuff). We were storing them for a builder friend, who then passed away & we inherited some good & not so good materials.

The weather is going to be a bit cooler for the next few weeks so I can keep the trout outside & keep the nutrients up to the plants for a bit longer now. I am going to build the pipework for the indoor set up but I have a funny feelig I am missing about 10cm of 1inch polypipe - just to go from the pump to an adapter. I will then use 1inch pvc pipe to the GB.

Off to scrounge in the shed!

Okay, I need to go to plan B.......plan A way too noisy!!!

Won't go down well with the 16yr old daughter when she comes home...

https://www.youtube.com/watch?v=Spd0WgT4jc4&feature=youtu.be

Mmmm.....plan B was to use the 12v 750gal bilge pump, (Plan A was 6000lph pond pump.)

Still very noisy - but it does move the water around well & I am sure the trout will like it.

I may be pushing the relatively good mother / daughter relationship too far here

The indoor system has been running for a few weeks with a 2000lph pump, without any complaints from the teenager.
It has cycled & currently has 10 trout in it. The seeds I scattered sprouted very quickly & became quite leggy as I didn't have a grow light organised. I am now running 2 fluros (t8s) but I think I need 3 or 4 to fit the width of the bath & to stop the plants leaning so much.
The water is not as cool as I thought it would be; between 20-21.5c but at least it won't reach much more & the trout should make it through summer. I will be bringing the rest of them inside shortly as we are expecting 40+ temps in a few days.


I am quite excited as my hoop shade/greenhouse over my outdoor setup is finally becoming a reality. We have decided to raise the height of the framework to accommodate the growbeds (it would have been hard work to move them otherwise) by building a wall & extending the uprights. It will more than triple the growing area I can use & I am already planning another system using DWC & wicking beds.




The shade cloth will go on tomorrow to help the plants over the coming hot days, but there will still be lots of work to remove lawn, level & lay gravel. It would be nice to pave the same as around my current GBs but it would cost a fortune & I would rather spend money on a bigger fish tank & the next system.


I am still struggling with the low pH - it only takes a day or 2 for things to drop back where I can't measure levels. This week I have added 2 desert spoons of hydrated lime, 3 days in a row & added 300ltrs of dam water with a pH of 7.8 & my latest reading is between 6.2-6.4. I have had better growth in some of the plants recently & I can just measure a slight trace of Nitrates. I am only running 6 of my 8 GBs to try to concentrate the nutrients to get the best growth.

The picture show some of the better growth I have had over the past few weeks.

These pictures show that I can't grow a zucchini in an aquaponics setup.

I have tried for 3 years - sometimes the seeds don't germinate when sown in the GB, sometimes they do, only to die at around the 4 leaf stage.
This time I bought seedlings & 2 have died & this 1 is really struggling. It is no more than 25cm across.
The healthy dirt plants were from the same punnet & I cooked the first fruit from them tonight. They are about 100cm across.

Not sure what I am doing wrong!

Today's progress

Hi team41, the expansion is looking good

what type of shade cloth are your going to use?

God bless, froggo

Hi Froggo,

The shadehouse came with 50% white shade cloth. I have also got plastic to put on during winter in an effort to keep things a bit warmer.