by Treetop » Thu Jul 14, 2011 3:01 am
Okay... ran into some issues, but have them sorted out.
first the duckweed wouldnt grow in full sun. and I have a larger tank now and cant easily move it so until next year I had to play with algae which isnt as useful as duckweed. (working on duckweed for next year)
So heres the score. I was looking to see if I could recirculate the water, keep it clean AND grow the food for the fish. Pretty sure I explained earlier that growing land based plants offers many negatives. I will get into that more if someone is curious as to why, but one reason is it costs more also the land based plants need the nitrification cycle and it takes a LOT more infrastructure. the food is also nutrient deficient. better to grow it in soil... hence the duckweed useful for ALL my other animals including the fish, and things like daphnia and other zooplankton which are easy to grow. since im growing carp I can supplement with ANYTHING else actually.
Next year I will be expanding into also growing other plants useful for food for myself, while also conditioning the water.
So since the duckweed wasnt working, that was out. So for now I have food for the fish. doesnt cost a lot at all.
So back to algae... algae and duckweed are some of the few plants that can use the ammonia directly out of the water. since duckweed isnt working where im set up now Ive been playing with algae. To date I still often use the fish water for the garden and add more fresh de chlorinated water. I have however perfected cleaning the water with algae!!! Ive used test strips to ensure the water is indeed clean, and its easy to gauge this without test strips now that I know what to look for....
I cut the top off of a 60 gallon drum. I fill it with fish water. I "seed" it with this algae I have. the algae grow FAST. I also grow daphnia and moina and other zooplankton in there, and they eat bacteria and other such things. they feed themselves basically. each day I pull out some of the algae, aafter I wait two days for it to start growing well. then usually about 5-6 days into it the algae stops growing fast. at this point it is in pretty good shape (still measurable levels of ammonia but well into the ideal range cleaner then most ponds or lakes) at that point I simply scoop it out into the big tank with the fish. and scoop fish water back into the drum. let the process start out again.
Im now to the point Im going to test this without taking out water for the garden and adding freshwater. Im going to rely on the algae alone. Im going to be setting up atleast 10 sixty gallon drums for growing algae. It might take more Im not sure yet. I will add more if need be. My main tank it about 700 gallons. As I said if I had a shadier place then duckweed would be grown instead. Which is a great feed for all types of animals from ducks and chickens to rabbits or fish. Nutrient dense. this would be ideal as its nearly as efficient for this as algae but is more useful then the algae. thats fine though. I will work with that next year....
I also set up two 5 gallon buckets with many holes in them. I put sponges and cloth in between the two. I run a water pump through this as a filter for about an hour a day. It keeps the water clear. I can also feed it manually as Im doing other things outside or with my kids, and get enough filtration to keep the water in good shape. Really I dont NEED to do this. I have a full array of lifeforms in there that are turning any gunk to soil as they would in a pond. But if I dont I also need more ammonia removal and will not be able to maintain a truly low level as easy. a 60 gallon tank can be filter like this in a few minutes manually pretty easy.
so.... now it is just a matter of how many algae tanks I will need. Doing this with duckweed will make needing food for the fish unnecessary (although my zooplankton take a chunk out of that already) but as i said part of this was to see just how cheap this could be done without NEEDING new water. and honestly adding new water all the time isnt ideal. Lots of life in the water of a pond. never change more then a third of the water at a time.
anyway it looks like for the price of aeration, a pump for an hour a day, a simple cheap filter I made, and the fish, tanks, and a few other things like my zooplankton, clams and snails. You could get everything but the tanks nearly anywhere in the country from most lakes. although you might not have the IDEAL species for each, that doesnt matter. so you could do it for the price of the tanks if need be, which actually could be made from clay. At lower densities you dont need aeration either. for the filter dried grasses would work. My point being is you could set up such a system for anywhere from free to 2-3k and grow any amount of fish your willing to invest to grow, or take the time to do the work...... It can be very little work, or a lot depends how much money you have to do it. But yep, it can be done cheap if need be......... and if i was set up for duckweed rather then algae I wouldnt need to but fish food at all. although I can feed these particular fish just about anything including many scraps. although you do have to kinda "train" them to eat new foods sometimes.
should also point out that the zooplankton growing in with the algae will eat bacteria and other things. they breed FAST. so if they water has a lot of bacteria the grow to high numbers and lower the levels of these things i the same way it would happen in a lake. I also have tanks growing these purpsely without the algae. Its a very interesting set of lifeforms. on a good day I can harvest a few ounces of them from a kiddy pool. to feed them I drop in a small chunk of manure that makes bacteria grow. Then they fest, and bred like mad. clouds of them. i have varieties that evolved in ponds without fish, so they are especially efficient at growing and breeding not needing to spend much energy on defense, like most zooplankton do, they are also larger then most that are in a lake. about the size of a BB and bigger. the fish LOVE these things. It builds their immune systems to eat live foods. Its carps favorite food when they have a choice. and its cheap for me to produce. couple it with duckweed as I get that going, and Im golden.
Now you could do all this for tilapia as well by the way. But you need a permit for tilapia in my state. so I dont have those. Both fish are bottom feeders in the wild and will get a poor taste. But both can be pretty good raised in clean water and fed well. Carp get a bad rap but I keep reading they can be tasty if raised right. I will let you all know if that is true.