Aquaponic Gardening

A Community and Forum For Aquaponic Gardeners

It's too hot for duckweed here in the desert so I decided to grow some algae in a kids pool. I added water, a little ammonia (a cap full a day), a little sea weed extract (a cap full a week), some aquaponic water from the system. I add a liter a day. and a lot of sun. I went hiking and found some algae in a pond. It took about a week to get going but now it's really cranking out the algae. I put some in a plastic bag and freeze it. Just to make sure I am not adding anything live to the system.


The tilapia go crazy for it. Even the little fish seem to get energized to eat it. 


Views: 1134

Reply to This

Replies to This Discussion

I plan to make some geodesic domes to put over the pools. It will keep them warmer in the winter and the bugs will be kept out. I don't think the bugs will bother the fish but they gross me out a little.

The other two kids pools are starting to put off algae. I have been making bigger treats for the fish now because they don't last long. I can make a 4 inch by 3 inch by 2 inch block now. That treat is from the original pool once a day. I am going to experiment with two 275 gallon IBC tanks to make algae. The IBC tanks are ones I collected to make a commercial Aquaponics system but they are just sitting there and I want to use them for something in the mean time.

Hi Chris,

Good thing you have extra algae growing space, in summer you'll have excess production and winter, while they won't die off they stop growing, so saving some by freezing it to tide you over winter is the way to go. Make hay(algae) while the sun shines to be used in times of scarcity. Do you notice any other species of algae growing along with the SP? My reason for asking is that at PH 10.3 only SP will grow but at lower PH's other types colonize and will eventually...............

No not really it's all green to me. I am taking it out so fast it really doesn't look any different yet.
What about using algae that grows in the stock troughs of our ranch? Would that be a good source to feed tilipia? I pray so because if that is the case then I may never have to buy food again lol.

Hi Debra,

Algae have adapted, as a primal source of life, to surviving for millions of years. They are a highly efficient basic form of life. They have the ability to suck "everything" from water, including pathogens, so it's very important we source them from sanitary environments.If your stock tanks are subject to antibiotics, steroids, harmful bacteria(eg. e-coli, salmonella etc) the fish and eventually humans can be at risk. That is why it is recommended growing algae in a remote controlled environment where we can better monitor the inputs of system water. 

Thank you Harold,


My stock tanks are for watering our stock (cows and sheep) and wildlife (deer, hogs, other wild animals) so I know they have exposure to, at minimum, e-coli!! How could I start algae for the fish? Just let it sit in the sun with the right pH as mentioned above? Can I start a large body of water, possible a child size swimming pool, with a small amount of the algae from the stock tank? I do have one source of algae that has not been exposed to any stock or wildlife because of the size, it is a cement tank that is about 10' tall or so. 

I have been freezing the algae to pasteurize it. I am not 100% sure if all bacteria is killed by freezing. It would be interesting to find out if it does kill it.

I am saving up some money to turn a 275 gallon IBC tank into a algae bio-reactor similar to the guys growing algae for fuel.

Chris, I have never heard of growing algae for fuel, sounds interesting!! 


How long have you been feeding your frozen algae to your fish? Do you use the algaesicle exclusively or as a 'treat' for your fish? 


I am not a fanatic for 'germs', meaning that I think dirt and exposure to some germs/bacteria is good for you. I grew up eating some fish my dad had cought out of our irrigation tank. These fish were exposed to anything and everything that went into the tank to drink....cows, sheep, goats, wildlife, horses I am still wondering about the algae from the troughs that I could use as some of the feeding or for a start in other pools/tanks that would be more controled as far as what has gone into them. What are your thoughts?

I collected 4 buckets of duckweed but they were growing on top of a filamentous algae that were stuck to the duckweed roots. I am drying the whole thing in the sun. Should be totally dry by tomorrow. I was wondering if the algae is edible for the Tilapia.



Hi All,

Chris freezing won't kill all bacteria and especially not salmonella or e-coli.

Debra-Yes, Tilapia  just love eating algae of most any type. Spirulina(which is what Chris is growing) has more nutritional benefits than the other types and it can be grown at high PH where E coli and salmonella cannot multiply. See more here

Hi Conrad,

Yes Tilapia do love Algae although I've never dried it to feed them. Drying is a good method for killing pathogens but other toxins and heavy metals may remain, so we still have to be cautious as to where we source them from.

Conrad Chin-Yee said:

I collected 4 buckets of duckweed but they were growing on top of a filamentous algae that were stuck to the duckweed roots. I am drying the whole thing in the sun. Should be totally dry by tomorrow. I was wondering if the algae is edible for the Tilapia.



Reply to Discussion


© 2022   Created by Sylvia Bernstein.   Powered by

Badges  |  Report an Issue  |  Terms of Service