Backyard Aquaponics
A place to discuss aquaponics

I don't think that Silver perch are bland Timmy. They are a good tasting fish and the method of cooking often has a bearing in these things.

Sounds like fun

Have read all of this thread now - so will make some more comments:

- one advantage of the silvers is that they are omnivorous. Barra are carnivorous so will not eat plant matter. I think we would all be shocked at how much algae from the sides of our tanks the silvers eat during the year. This will be one disadvantage once I move my tanks inside the shed. Although I did not do it much first time around, in the long run I'd like to supplement my perch's diet as much as possible with home grown green stuff.
- the silvers are a very nice tasting fish, as are the jades. The only downside is the significatn fat deposits - jades are worse tahn silvers). Although these are good fats, can get sickly if you eat too much, so portion control and cooking method is key (as well as eating around the main fatty areas). Both these types of fish win hands down over trout in the taste stakes IMHO and the bone structure is much friendlier also. Me and the kids ate one of my big silvers on the weekend, filleted because this is how the kisd like it. Not a single bone.
- in my experience the silvers and jades are very very hardy. The jades are quick growing.
- time to grow-out becomes less of an issue for a backyard grower just supplying family, once you have a mature decent sized system up and going and provided new fish are being brought into the equation at appropriate intervals. FCR is an issue though - from a cost perspective and trout will win hands down there. Though there is the option with perch of supplementing with non-purchased foods to reduce cost and add diet variety.
- although I am growing some barra right now, I'm not sure this is something I will do again unless I can get advanced fingerlings (say 7 to 10 cm). Has been a pain in the bum at the start. Also, I have no intentions long term of heating via electricity, so unless I can get some solar heating going to at least extend the season, then Barra will not be a long term proposition for me.

Stu you've been saying this for a long time now, when are they coming?

Think they are on a swimming expedition from nth Qld

"With 10,000 of the blighters arriving within weeks"

What are you going to house that many fish in Mon??
Do you have dams as well as tanks?

Where you been troutman

I have had confirmation they are halfway to their shipping size. I will make a post when they are a week away. Don't worry, I am as eager as anyone to get them, things are pretty quiet here without them lol

Troutman, we have a small fish farm here. The silvers will be our fish to growout over the next 2 years.

Can't wait, remember I'm dibs for 200

TimC
Heating the aquariums inside the house, but the larger ones are mixed in with the SP outside - not heated. Seem to survive fine over winter.

i have personally seen silvers take worse conditions then trout (eg high ammonia, and ,low DO) as for barra, the only experience i have had with them are eating them, but i reckon they are better eating then trout (never eaten silvers so can't compare there)

So what size tilapia did you have in the cold tanks? I am curious now whether to attempt tilapia all year round, and just have the breeders/fry in the heated tanks... I bet they didn't eat much during winter...

That is the other thing too... A fish that will 'survive' over winter, but not eat would be losing mass during this time making the grow out time longer. Does it fail to become economically viable if there is a negative growth for half the year?

between 2 & 3 inches. all fish didn't eat much over winter, but now they are hungry all the time.

My thoughts on food conversion ratio and wintering:
I guess it depends on your preference for vegies or fish.
- All food entering eaten by the fish goes towards either fish growth or waste for plant growth
- Fish with a FCR close to 1:1 (like barra apparently) in theory give you more fish meat for your feed input than fish with a lower FCR (like SP), but in theory put less back into the system for plants to use.
- If fish are losing weight over winter, the weight they lose is going back into ammonia etc for plant use.
- It's similar (in my mind at least) to the tradeoff between flowering/fruiting plants and leavy vegies...the climatic conditions, nutrient balance etc affect the balance of vegetative and reproductive growth. We have some control over what we promote, depending on what we like growing and eating.

I think SP are fun, hardy and active. They certainly don't eat like trout in winter, or like barra in summer, but they are a very useful fishie.

Although they nearly killed a very large goldie (as big as the SP) that had strayed in through a siphon pipe at least it was injured enough for me to finally fish it out and rescue it to another tank...hopefully it survives.

Agree there Steem, I had no problems with nute deficiency over the winter period although the SP stopped eating, so I would say it is only a weight loss thing