Backyard Aquaponics
A place to discuss aquaponics

Hi there everyone

I'm Dean, I live in Perth's southern suburbs, and jumped into the aquaponics world in May this year with the purchase of a Salad Bar system from BYAP. Without spruiking it too much, it's a fibreglass system with a 200L GB and 700L FT. I've taken a few photos & videos, which I'll add here as they arrive. My initial growbed contained cos lettuce, cabbage, cauliflower, celery, broccoli (seedlings) & strawberry (advanced seedlings), combined with my dream of 10 trout, and 10 marron.

After initially setting it up and waiting 24 hours, I came into problems. I bought 10 trout, and within a week or so that regularly dwindled to one lone survivor, hereafter named #10. With the benefit of hindsight, I should've waited a bit longer than 24 hours but I was too eager to join the aquaponics world. Here is the link: viewtopic.php?f=2&t=12813

Here is a short video of the trout "flashing". As you can see the poor guy doesn't look happy, the next day I fished the body out of the tank. From memory, this was #6, #7 or #8.




I've also attached a picture of how the system is setup at my residence - looking roughly NW.

June/July: after the trout deaths, I waited a few more weeks and took readings. Around mid-June, everything seemed to have cycled so I went out to Golden Ponds and picked up 7 trout to go along with #10 and the ten marron.

Here's a picture of the trout in their new home. I immediately noticed that the new trout swam a lot more than #10, who was quite happy to hide in the corner with the marron.

The green mesh basket's are a quick marron castle I made for them to get some air. I thought I had 'escape-proofed' this by being in the centre of the tank, yet I still find some Alcatraz attempts....

I ended up cable-tying the loose basket on top of the other two, which enabled quite a fair bit of room for the marron to hide and hang onto. I've since removed this from the tank, which is explained in the next post.

July & August: Everything was going awesome as I was running the system on a CF basis. The trout were gaining weight, always hungry when I fed them, and the ammonia and nitrite were playing the game. Nitrates were at 80-160ppm, and pH was steady at 6.6 ish.

Around early August, pH had dropped to 6.1 ish (well, 6.0 to 6.4), so on the 9th of August I added shellgrit to buffer the pH up. Everything else was ok. On the 14th, I decided to switch from CF to F&D (Again, don't ask me why, I thought it was a good idea). Check the next post for all the details...

Here's a video of the marron trying to escape...




And on the 8th of August, feeding the trout. Note that the water is nice and clear. Readings this day came back at 6.1pH, 0.25 Amm, 80-160 Ate, 0.0 Ite, 13.5 degrees.





Finally, here's some pictures of the growbed. (Note, after the frost we had the cos lettuce got frozen, which was replaced by some spring onions and tomatoes that had grown of their own accord in the front yard). On the second photo you can also see where I've chucked some rocket and mizuna (leafy things in salad) where some cos lettuce used to reside.

And for my ease, check this link out: viewtopic.php?f=1&t=13441

Otherwise, the video explains most of my idiocy

And my most recent video, post water change, of a marron trying to escape. This concerns me, as the marron have always been happy to live in the tank

Perhaps the water and funk in the system will settle down over the next few days and they'll be happy again???

Thanks for the vid's and your plant growth is great

Your marron are bailing because your PH is too low, acidic water will soften their exoskeleton. A PH that low is killing them. Marron like pristine water quality, add some shell grit for buffering and it will also assist in the take up of calcium for shell health.

Make sure you have plenty of aeration and salt to 2ppt.

Personally I would only have 4-5 marron that size max in that FT.

Marron are very difficult to raise in hard bottom tanks sorry.

Hi Charlie - thanks for the positive reinforcement - guess somethings going right!! haha

I should add that I added shellgrit 2-3 weeks ago and the pH has raised already from 6.1ish to 6.4-6.6. I also salted (~2ppt) in mid-late June, and again today (~800g or 1ppt thereabouts). Silly question, without buying a salt meter (I know there's a word for it!!) how long does the salt last for? I've only one strawberry plant in the GB which has been largely crowded out by the cabbage and cauliflower, so I'm thinking I can chuck that in a garden bed elsewhere and salt the system to the forum's recommendations.

As I explained in the video (but not on the forum); the cause of all the murky water was a dead marron. I originally thought it was two; as there was a hard shell and the marron itself with a soft shell. Doing the maths, there was only one marron 'missing' (ie I got ten in May, and there's clearly nine as can be seen in the video). Having a think about it later, is it fair to assume that the marron had outgrown it's shell, and gotten attacked & killed whilst vulnerable? From memory, it had both 'big' claws on it (however two or three 'legs' were on the floor which alerted me to the problem).

The marron were ~100g each in May if that helps, and the breeder reckoned that optimum size was 180g. I'm fairly confident they are still 100g Long term I'd like to keep a few at all times, but there might be one or three in the pot for a Christmas meal this year. I'll take a picture of the marron Castle for your interest over the next day or two, there's a fair few spots for them to hide along with the 8 or 9 PVC tubes that are in the tank. Either which way, 4-5 would be comfortable if they are 180g, then again, that's dinner time for me

In regards to aeration, after the trout death incident I bought a two airstone pump AC/DC backup air pump which I strongly believe has kept all the fish & marron alive. And in other news, the Boss/Ministry of Finance has said that upgrades are allowed ... I'll wait for a few months to figure out finances myself and hopefully upgrade from there. Thanks AP for a hobby, addiction, and stress reliever all in one

Deano

Hi Deano, hope I wasnt being too forward sorry, as you may have guessed our aussie crustaceans are my soft spot

+1 for the shell grit so keep that up, try get up over 7 and they will be much happier.

+1 for the salt, you could prob leave it at that. (salinity refractometer is the word you were looking for) Salt really only dissipates through transpiration and water changes so it stays a while.

+1 for lots of air.

Theres a very good chance when the marron maulted he was attacked at his most vulnerable exactly as you have said, this is the issue with the amount of marron you have in a small area compounded with low PH. Limit the numbers and this can be avoided, eat a few mate you can always buy more

If you want to keep them all Id separate them into individual crates, this is what I do with my big ones.

Keep us posted mate and Im happy to help with any further queries

The veges bed looks great Dean, thanks for posting pics and videos. And permission to expand, even better. thumbs up.

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Good work dean. I'm glad you didn't throw in the towel on the first hurdle.

Keep it up, things will get easier as u learn.

Expand now while she remembers, in a couple of months who knows.

so true!!

Charlie, I'm a big fan of marron & yabbies myself too. We had Christmas on the farm every year and all the "Men" would go out to the dams and get buckets of yabbies for yabby cocktails. When you say individidual crates, have you got a pic or an explanation of them?

Thanks again

Deano

Harvest 16/9/2012

6/8 fish eaten, smallest was 220g odd and largest was 320g odd.

All six tasted fantastic (according to all involved) with a simple lemon/pepper/seasalt & AP vegetables recipe.

For those interested, #10 survives with the last of the Golden Ponds trout, these will meet a similar fate in 3-4 weeks or so, then I'll chuck in 10 or 12 barramundi hopefully

It's been a thoroughly enjoyable experience so far, and I'm looking forward to the summer harvest of barramundi and salad vegies. Thanks to all at BYAP for their support and here's to many more harvests!!!

Glad to see Dean and happy to hear they were enjoyed. Thanks so much for sharing the pics with us.

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