Backyard Aquaponics
A place to discuss aquaponics

I'm sure this has been addressed many times before, but I can't seem to find it on the forum, or anywhere obvious online.

Does anybody have a table / chart for Trout growth rates? I'm trying to work out when we might be getting them to eating size, plus when their growth rate starts to slow - i.e. when it's best to cull them and start the next set.

Can anyone point me in the right direction? Maybe it's worth a sticky?

Dont think anyone has made a graph of trout length to weight like they have with silver perch . In my very limited experience I know that trout grow very quickly as I have had mine for not quite 3 months and I reckon another month will see the first one in the smoker.
Maybe as we harvest this year we could put something together to get a good idea

I think one was started on silver perch, probably not trout as yet.....

Thanks guys, I guess I was thinking of the weight/time graph rather than a length/weight (although that'd be useful too)

Interesting to know you're getting them out after about 3 months - that's very promising!

Here's mine. Sampled every 2 weeks.

I feed ~2% of body weight in feed per day, adjusted weekly.

I plan on keeping this record updated until the final cull.

Cheers,
James

Weight is total weight of fish sampled. Avg Weight is total / # fish sampled. total/kg is avg weight * total trout in tank (I have 120)

I did say about another month so that will be 4 months and they were 125mm to begin with

Nice table James, good work
I have been tempted to net some of mine to see how big they are and what they weigh, but dont want to stress them
I guess if you have been netting some every couple of weeks and weighing them, and havent lost any, its not too stressful eh

Trout take being handled quite well. I quite often having people visiting me, and the fish get netted several times a week.

Good Chart MrO

Fantastic - thanks!

no worries guys. I'll keep it updated. IIRC I worked out based on current growth they'd be close to 500gm by start of december so I guess they're on track.

I have one of those 'fish safe' nets. You can buy them at the camping stores. Doesn't damage the scales. Think mine was about $25 from BCF. I also net at feeding time, so net is in water, trout hitting feed on surface, lift net up.. Chasing them around the tank trying to catch them would be more stressfull IMO.

Cool, I will net a couple and see what they weigh and add the results to this thread. Might be a couple of days away tho

is that 3% a figure for optimal growth, or is that just what balances your system the best?

i give my 15 trout a 1 1/4 tbspn a day, theyre at 120gramms after 11 weeks. started about 50grams.
this sleems slow now that i do the maths . . .
cheers
ben

Netted three on the weekend and the largest was 22cm and 200g. I reckon there are bigger ones in the tank but they are quicker and harder to catch.

Hi Everyone,

Here is a chart of my trout ( hopefully works as am new and not posted before). I put my trout in on the 18/04/10 and the average wt was 10g, I have been taking an average wt every 4 weeks and recording the amount of feed used. I started out adding a set ratio of feed but soon changed to feeding a few times a day if possible and slowly adding food until they stopped attacking it at the surface ( only a minute or so each feed) as was worried i might overfeed them. But also wonder if i am under feeding them. So i am glad others may have some growth rate data and it may help to optimise feeding amounts??

MrOrange's growth rates are very similar as the curve is almost the same except it sits lower due to a lower starting fish wt at the corresponding date. I didnt put it on the chart as thought i should ask first before including other peoples data on the chart. It would be good if we could get a number of people with different data to get some sort of average.



My feed per body wt has been dropping as the fish are getting bigger but not sure if this is due to the fish getting bigger or that it is colder and the fish have slowed down a bit on their food. has ranged from 2.8% and is down to 1.5% at the last weigh in.

Also MrOrange do you have total feed used, to weight of fish as i am interested in what what sort of feed conversion ratios people are getting, At the moment i seem to be getting about 1.2 ( working on the assumption no fish have died and the original number are still in the tank) but that wont be confirmed until all the fish are removed.

Next weigh in is due next week so will update the chart then.

Cheers Shayne

that is one handy data set . . . wish mine were growing that fast