Backyard Aquaponics
A place to discuss aquaponics

Fishrcool,

Check out this thread.

http://www.backyardaquaponics.com/forum/viewtopic.php?f=1&t=5085&hilit=rock+dust

Thought I would post an update on my system. The vegies are taking off. We have been harvesting brocolli, chinese cabbage, parsley, silber beat, and cauli. Everything is coming to an end. I am thinking of planting some tomatoes and capsicum. I want to sow them directly. Do you think it is too early to be sowing them? I found some tomato seedlings that had sprouted in the dirt garden. I think I will put some in the next week or two.

I have lettuce growing in floating rafts on top of the fish tank. They grow so quickly. I have also planted some in rafts on top of the sump tank. They haven't grown at all. The bed is facing South and I don't think it receives enough light.

The fish have grown a lot. I think they are still a long way from harvest size. I weighed a few and they are about 100 - 130grams each. I have slowly increased their food. I am currently feeding them 1/2 cup a day morning and night.... for 74 fish. I have started to increase that amount the last few days but my ammonia levels have increased to 1, and nitrite .25. I don't think that is too serious. I think I will keep my feed levels the same for a few days then increase again.

I really need to build an overflow pipe on my fish tank. We have had a lot of rain in the last week and my fish tank keeps on overflowing all over the ground....not the best. Our next busy bee will include....moving the pump so it is exactly in the middle of the fish tank, reshaping the floating raft in the fish tank so it can spin around in a circle for easy harvesting of plants, cuting some more holes for pots in the floating raft and building an overflow pipe.

After these things are done I would like to work on building a deck up to the fish tank so the kids can see in. When we have enough money I would like to install the fourth grow bed. I am thinking of putting it at a really low height...or building steps all around it so the kids can be a bit more involved. We are going to insulate the fish tank and tidy up the child proof tops on the tanks. I'll try and post some picture soon.

Here are some pictures of my system. A few weeks ago I had some problems with diseases. I don't know what was wrong but I sprayed the plants with seasol and they seemed to go away. The bottom leaves of the broccoli still look a bit sick, and the bottom leaves on the chinese cabbage seem to die and rot. The plants still look healthy overall.

I forgot to add in my update that my pH has dropped to about 6. I have hung some seashells into a stocking under the return water from the grow beds. I am not sure how much you need to add to make a difference.

diseased plants

Pictures of the rafts in the fish tank and sump.

Today we ate our first trout. It was still little, around 160grams. It tasted fantastic. We have done some running repairs on the system.

What is the best way of removing solids from the bottom of the fish tank? I have the pump in the middle of the tank and the return water is at an angle. I think there is too much 'gunk' on the bottom.

It is very difficult to see the fish. The water seems to have a lot of floating 'bits' in it. It cuts down the visability. The other issue is the sides of the tank have algae growing on them. The algae is like little strings around 2 cm long. This makes the water so dark that you can't see the bottom of the tank.

What is the best way of removing this algae? Is their any fish that you can put in there that will eat the algae, which the trout wont eat? I have access to my Dad's koi. They are very large - over 7 years old. Should I get a couple of these and put them into the tank? How will they go with the trout....or barramundi (in summer)?

the system is looking fantastic overall. The growth has been amazing. I think I will keep the fish on the same feeding schedule for a bit longer (1 cup a day for 74 fish). My ammonia level was still one today. Hopefully we haven't upset the system today by disturbing the 'gunk' on the bottom.

Goldfish - they will graze on that stuff all day, and grow big and strong too! Allowing you to sell them off at a profit in a year or so

Woohoo trout dinner, Well done, I hope you took photos.

Get the Koi in there ASAP, Trout are very suscebtable to crap on the bottom of their tank. Avoid sirring it up while the Trout are in the tank, kills them very quickly. The best way to remove solids from the bottom is one of the venturi cleaners you can get from pet shops, sucks up the stuff while draining it elsewhere.

Once the solids are removed make sure you have a good swilring action in the tank to stop it occuring again. Sounds like you need a lot more water flow.

I'll go and have a look at a venturi cleaner. Will the trout and koi live in harmony? Will they try and eat each other? Do koi actually eat algae, or am I better to get goldfish? If I do get goldfishwill it be okay to get small ones from a pet shop, or will I need to get them bigger? the trout are around 20 - 25 cm long and around 160 grams.

I think the water flow is okay. I have it pumping for 15 minutes every hour. when I scoop the bottom of the tank with a fine net I don't get 'heaps' of gunk. I was surprised at how much was floating around when we removed the pump. It didn't look like fish food. I have moved the pump into the middle so hopefully that will help.

thanks for everyones help.

Do not get small goldfishes from the pet shop unless your definition of small is bigger or of similar size to the trout. My trouts were about 10-15cm and when I put them into the tank with goldfishes (about 4-5cm), in the next 10mins, a goldfish was floating on the surface... If they ended up as trout food it is fine, but if they are attacked, and died, but not eaten. You will have dead fish in your tank.. which IMO is worse than algae if you did not manage to take the dead fish out early.

That is what I am worried about ivansng. The trout are getting quite big now, I think I would find it difficult to get goldfish big enough.

My Dad's Koi are very large so I don't think they would be eaten. My Dad doesn't think they will eat the algae as his pond has heaps of algae growing in it. I'm not sure what my options are.

I have read somewhere that koi would definitely eat algae but only if there isn't any other food source. So don't feed them. Only thing is that will they join the trout party when it comes to trout feeding time. If they do, well they will definitely leave the algae alone. If they don't, great. Don't feed them anything else.

I would say not to bother with goldfish. The key to algae being problematic is the amount. If your tank is heavily shaded it probably can not have a dangerous amt of algae growing. If it is not heavily shaded, do so and the algae will gradually die back. Or don't worry about thread algae: I've mostly heard of the single -cell stuff being a problem (pea-soup water). How dense would thread algae need to be to create a problem? Wouldn't a nice 2-cm rug (or a ten cm rug over a fifth of the tank) of the stuff be fairly harmless?

OK, I'm ducking down for the expected storm. *grin*

I don't think it is real harmful, it just stops your visability. I can't see the fish at all because the sides of the tank are so dark. The tank is mainly covered. We have a floating raft on 2/3 of it and a shade cloth over the remaining bit. The only problem with the raft is that there is a 15 cm gap around the outside (to allow for the raft to go up and down and get around the pipes). so the fish tank is covered except for that gap which can't be removed unless you take out the floating raft.