Backyard Aquaponics
A place to discuss aquaponics

Hi All,
Quick introduction, Just set up my first Aquaponics system in barrels (4x 200ltr with yabbies & 3 x lengthways barrel grow beds) has been circulating now for about 4 weeks with nil problems, small amount of plant growth. For some reason this morning I placed my hand into my central yabbie drum and removed 6 dead yabbies and one from another drum. They are stocked at 25 yabbies to 200lts with plenty of PVC hiding holes and climbing structure. Have been fed 3 times with a small hand full of potato and carrot per drum, chopped and partially cooked. The system has been on flood and drain 15min on and 45 off. Though this morning I have just changed to 30/30 to increase circulation/oxygenation. Would appreciate any thoughts on Cause of death, feeding

Steve

Hi there and welcome to the forum...

If you search the forum, I think you will find that there are also comments about people losing yabbies in their AP system... and often without known reason...

But the thing to note is that yabbies fight regardless of how many hides you have. I think the recommended stocking level is about 10 yabbies per square metre of horizontal space... From memory, yabbies can survive in pretty low dissolved oxygen levels so I don't believe oxygen is your issue..

On another note, what is your nitrate level? Not sure if the yabbies alone will produce sufficient waste for nutrient generation for plant growth...

I lost a crayfish last night. It is pretty obviouse when you loose them to battle...they will be dismembered and partially eaten. And the crayfish we have here can live a very long time in very pore conditions. I would suspect disease if it were me.

I lose quite a few due to fighting and also when they moult, I think my catfish pick them to death when they are soft

I know all about dead yabbies as they were the cause of losing my fish they can die for no reason or fighting, they need plenty of hides or space or they will fight for territory, and fight to the death, mine appeared to just die as I had several floaters during molting, as FF said above they more vulnerable at this stage due soft shell, mine died in hides and contaminated the water, for me I'm over yabbies as these things can happen, as ivan also said above there are many stories of dead yabbies, better bottom feeders are Cobbler/Catfish or I find now system is settled marron are fine as they are not aggressive, but marron are native to WA only, maybe similar to red claw over there, air isn't your problem, yabbies are just a pain in the arse

Now they were definitely dead? We've often been told by customers that there are dead yabbies, but they were just moulted shells.

well mine smelled dead
But yabbies generally eat their shell straight away, I rarely find a full shell but often find bits floating, well not anymore as they are all dead now, after turning orange

Hi All,

Thank you for your replies, There was some battle scars on one of the yabbies, they seemed to have died over a few days and some did smell. The others in the drums are quite lively so I'm not really concerned maybe they are just establishing a natural equilibrium?? I have my test kit on order. pH last check sat right on neutral. Would appreciate any suggestions with feeding. Carrots and potato I have seen used on the forum but how much?

Thanks

Says, I was feeding mine marron pellets, same size as chook pellets and about a handful once a week for 200 yabbies, lupins are also used but only 1 or 2 per week per yabbie, Doesn't matter how happy and well fed your yabbies are they will still fight because they are aggressive by nature, the only way to stop the fighting is to have 1 only in tank, which is useless really

Nocky, it sounds like you had enough of yabbies already...

Yes Ivan, there are plenty in the dams to eat, my main reason for yabbies was to clean the bottom of the tank, I will get some cobbler when possible to do that, I prefer marron in tank but had difficulties with he in my first system, but marron seem fine in a tank by themselves, I had about 200 yabbies to start with, when we decided to get rid of them we ate about 14 some had died and floated, maybe still a couple left in tank but marron will sort them out

Yep, I'm with Nocky - gunna get rid of mine soon in a cook-up (note to self: must remember to get photos) - could be putting something useful in there, such as more fish.

Well yabbies do not need a recirculating system (AP), they will grow alright in a pond or hole without filtration but with duckweed as the top floating cover to stop algae growth. That's if you want to see them occasionally, otherwise they will be alright in algae water as well...

I suppose it is because they do not produce too much ammonia to start with... and because they can survive in low dissolved oxygen situation...

You just might be surprised how much ammonia a bunch of yabbies can generate....

My blue barrel system was initially, and often still is.... powered exclusively by yabbies...

The experiment was worth it Nigel, I will be getting some cobbler after seeding, will keep you tuned