Backyard Aquaponics
A place to discuss aquaponics

I tend to drift in and out of interest in forums, so I may not follow through.

With that caveat in mind, I recently finished setting up a small, in-house aquaponics system, currently using a 55-gallon aquarium and two 5-gallon plastic bins for growbeds, and oscars for fish. I will use this thread to post periodic updates on my progress.

The aquarium now contains 4 gold gouramis, 2.5" - 3.5" long, plus 5 newly acquired oscars, each 1.25" - 2" long. I expect the gouramis will start to disappear in a few months, shortly after the oscars exceed them in size.

My goal is to get at least one adult breeding pair of oscars, plus one or two others grown large enough to try them out as a food fish. Provided they seem like decent fish for aquaculture, I will set up a larger, outdoor tank where I can transfer fry in the spring and--hopefully--harvest fillet-sized fish before it gets cold in the fall. That, however, will require a happy adult breeding pair, and so, will not happen before the spring of 2009.

I planted pre-sprouted lettuce and spinach seeds in the growbeds yesterday.

The entire system is on a 45-minute flood-&-drain cycle. The aquarium still has the undergravel filtration system running inside of it, plus a back filter.

The pump to the growbeds is a tiny thing salvaged from an old miniature "zen rock fountain" thingy. It is located inside of the back filter, on the clean side of the actual mechanical filter.

The water in the tank is currently quite cool, by aquarium standards (68-70 F). I'm working on a cheap/free way of increasing the temp. Oscars should tolerate the low temps (and the gouramis have been living with it for over a year), but it will significantly slow their growth.

One of the biggest concerns is about the growth rate of oscars. From a decorative-aquarium standpoint, they have a very fast growth rate. However, by aquaculture standards, oscars may or may not be fast growers. Additionally, I've seen much anecdotal evidence to suggest that their growth rate can be highly variable, according to tank cleanliness, food-type, water temperature, individual genetics, and perhaps other, undocumented, influences.

The long and the short of it is, we'll see. I will keep reasonably accurate notes on their growth rates, along with feeding and tank conditions.

Currently, oscars are living in very clean, 'aquarium-standard' water conditions. Temps are--as noted--around 68-70 F. They are fed 1-2 times a day. Currently, they are eating, primarily, standard aquarium flake fish food, with the occasional bit of worm (red wigglers, from vermicomposter).

In time, I plan to feed them primarily worms from my vermicomposter, plus bits of dry dogfood, rabbit-food, and vegetable kitchen scraps (if they like them).

Keep in mind, I am brand-new to aquaponics, and welcome feedback and suggestions.

Sounds interesting.

If you are going to eat the fish, check the dog food and rabbit food for things you wouldn't want to eat for yourself. Ethyoxyquin bears particular attention.

What kind of gourami are they?

gold (or golden) gouramis. I intended to use them originally (not as food fish, just waste providers for plants), as they are supposed to be live breeders, but these gouramis have been annoyingly celibate (even after several months of warm--breeding--temps) ... so now they are oscar feed.

oh

I bought some 2 or 3 lb Oscars from a guy who listed them on Craigslist. He said he bought them at Walmart less than a year before at the 1.5" size. And fed them beef heart. They wouldn't touch feeder goldfish. Only fish food and beef heart. Unfortunately I let the tank get too cold and they died one after another.

Apparently, I was keeping it too cold for them, as well. One oscar died last night, and a couple of the others were looking a bit wonky.

I've increased the water temperature to 72-74 F, and also added a second heater. I was using a single 100-watt heater, and I think it wasn't strong enough to keep the temperature up where it belongs.

My house thermostat has been set to cool off a lot at night and during the day when I'm at work. Now I suspect that, during those times, the tank water temperature was dropping below 68, perhaps far below, and then coming back up to 68 when the rest of the house warmed up.

So I added a second heater, and reset my thermostat to keep the house warmer while I'm gone. It's about time for the snakes to come out of hibernation, anyway.

I may yet lose more of the oscars, but as of this morning, they were looking a lot better (except for the dead one, of course).

emsjoflo ... any chance you remember what temperature you kept them at, that caused them to die?

Nope, no thermometer in the water. I just know that as the temperature of the water went down, they did worse

Hi rainbird
You'd be better keeping them at around 28-30°C all day long.
Keep an eye on them because cold shock can cause a bacteria or fungus infection that is easy to treat if it is done on time, maybe even put 3 ppm (3 g/L) of salt for a few days as a preventive solution. Won't harm the plants but prevents of any weakness of the fishes immune system.
I've found some info on fish farming Oscars in french guyana for food, they must be good to eat and they are said to have a good growth and are easy to reproduce.
Good luck with your system.
Amacafish

Isn't that around 82-86 F ? Isn't that too warm? Aquarium recommendations for oscars are 72-82 F.

At any rate, in the end, 3 of them died--presumably from cold shock. On the plus side, if I get a breeder from one of the two that survived, then I've just successfully selected for cold hardiness.

Currently, keeping the tank at 72-74 F, and temps are now definitely staying in that range. One--possibly both--of the oscars showed early symptoms of Ich or some other fungal infection. Currently treating with Rid-Ich, an aquarium anti-Ich medication, and also with salt.

Water testing shows ammonia, nitrites and nitrates all at healthy levels, although pH is high (7.6+).

In the next week or two, I will be gradually bringing the temperature up another couple of degrees. I will not be getting any additional oscars for at least a week or two, to give the tank a chance to stabilize, make sure everyone is healthy, etc. However, I don't want to wait too long, either, as the current oscars are already visibly larger.

Got additional information on oscars. They pair up readily ... but not necessarily male-to-female. Two females or two males will often pair up, too. So, the only low-tech way to be sure of a breeding pair is ... baby oscars.

If I decide to stay with oscars for any length of time, I will need a larger tank, or a second one. A 55-gallon tank is barely large enough for one adult pair, and if I need to maintain multiple pairs until I identify a breeding pair, this one tank is just not going to be sufficient.

ps: I'd still rather have tilapia.

raising your temp to 28-30 will also shorten the life cycle of ich to mere days making treatment more effective sa they are only treatable in the free floating stage of life.

Thanks, Steve. I've heard that warmer temps are good for Ich (meaning, good to get rid of it). However, that is a 10-12 F temperature increase; wouldn't that shock the fish?

yep, dont do it all at once, and MAKE SURE you are treating the ich or else all it will do is speed the reproduction of the ich.

Personally i dont like the commercial meds, i liken them to chemo, you're lucky if it gets the disease before it gets the patient. Have had much sucess with high salt conc. 3ppt CHANGE in salinity + high (as high as the fish will tolerate) temps.

water changes can also be useful becasue it changes out any ich in its free floating stage along with the water, although i only ever did one 50% chane while treating with salt (IF you can have water stored with the exact temp /ph of your tank water, to prevent further stress)

Something to watch out for with larger Oscars is that they will attack the little indicator light on most tank heaters if they see it. I lost 6 +8" Oscars when they broke the heater outer glass several years back.

With ich, it HATES high temps. If you raise the temperature to 30°C for an extended period of time this will help to disrupt the ich lifecycle and kill remaining spores in the tank without the need for salt or medications. Used prophylactically it will also reduce the risk of an ich outbreak EVER occuring drastically. The added benefit of using high temperatures prophylactically is that the metabollic rate will be increased and you will consequently experience high rates of growth (and waste production... catch 22 situation... to keep oscars alive all year round you need to supply warm water. Plants growing out of the water in an AP environment will not have this same heating. The oscars will produce waste all through winter because they won't slow down and the plants will slow do dramatically during this time. You'll probably have to supplement the filtration during winter with a biofilter of some kind. If you ARE going to eat the oscars at some date I wouldn't be using meds available from aquarium stores as they haven't been tested to be safe for use with livestock intended fohumna consumption.

Oscars are notorious heater breakers - so I go stainless steel heaters with them now. Scary when they pick them up and belt them against the side of the tank though