Backyard Aquaponics
A place to discuss aquaponics

Will I be successful in growing the basic Vegi's if I am understocked with fish? At the moment I have 8,000 Litres but only about 70 Goldfish and about 20 other natives ( Rainbows and Blue Eyes ) I know in another year or so the numbers will increase as they are breeding and I have found fry but what numbers would you expect to have to make things work.

Also, having Green Water verse Clear water. In the past few weeks the Water has gone from crystal clear to green because of the warmer weather I expect. I'm now debating if clearing this up will also effect the plant growth? Water has been established for about 3 months and still to begin with planting.

no hard and fast answer. if you can get the nitrate levels up (even the lowest detectable readings on our test kit is enough) and then only plant the amount of plants that your fish will support you should be ok.

I do know that julie had problems with her 30KL pool and small number of fish with never being able to have enough nutrients.

you might even be able to get the initial readings by adding another ammonia source then balance the fish to plants

This is what I fear now, I think I will be down on nutrients because of the problem of more water then fish. In this case is there something I can add to the water to improve both conditions for Fish and future Plants? Or is this something that would just 'Wash Away' faster then I could keep it up? Is there a Test to find the amount of nutrients exist at the moment?

nitrate test is the one you want, but you may as well buy a "master test kit" from joel or monya.

the price you'd get it for (it contains 4 types of tests) is only slightly more than you'd pay in an aquarium for just the nitrate test.


what you need to visualize is that if the amount of plants you put in is balanced to the amount of waste your fish are producing the the NET gain or loss of nutrients will be ZERO.

you may need to boost the nutes up to a certain level and then try not to plant too many plants.

a nitrate test kit will allow you to track the nutrient.

or you could plant to many trees and go for a wander late each night after a few beers

You will need to add Ammonia by one way or the other, to try and get some nitrate readings - however I have never had a nitrate reading in my 8000l tank. Everything still grows ok, just add seasol.

You will be surprised just how much can you grow from only a small amount of fish.

While we are on the subject of fish tanks, Do I need to have pebbles in the bottom for any specific reason?

jack

Nope... what specific reason would you want them.... unless you have a species of breeding fish that needs pebbles/gravel...

Catfish and yabbies like pebbles or rocks on the bottom. My goldies love having mussels on the bottom in a group. Draw back is there are more places for crap to build up in. A lot of aquariums use a layer of gravel(rocks etc) and in my saltwater system we have bristle worms that live there cleaning up the waste. But in an aquarium they have to manually clean it.

Better question. Are there fresh water bristle worms?

If there is lots and lots of O2 in the water, you could let composting worms live in the gravel in a fresh water aquarium. They can actually survive under water if there is enough O2 in it provided the fish don't eat them.

As to large system with minimal fish. It can still work to a point. There are ways, I actually have a system with no fish but some people find the idea pee ponics distasteful even if the veggies are fine. My aquarium system has had only one lonely fish for months now and it's growing lettuce and house plants.

Even in a big system with a full load of fish, aquaponics is always a balancing act. It is winter here now and with the cool temperatures my fish are not eating much and many of the plants are looking a bit yellow around the older leaves.

The green water situation usually clears up. You might need to shade the fish tank heavily if it doesn't clear up on it's own though.