All times are UTC + 8 hours




Post new topic Reply to topic  [ 57 posts ]  Go to page Previous  1, 2, 3, 4  Next
Author Message
PostPosted: Apr 10th, '14, 02:34 
A posting God
A posting God

Joined: Apr 8th, '10, 23:51
Posts: 2017
Location: Fairport Harbor, OH
Gender: Male
Are you human?: yes
Location: fairport harbor ohio-on lake erie
i've been growing duckweed for about 4 years now.. mostly to consume nutrients in my crayfish tanks, but excess gets fed to the tilapia.. the colony does drop when it gets into the 40's, but i have not had a complete die off,
this is inside, with just flourescent lights.. i feed quite a bit to the tilapia during the warmer months


Top
 Profile  
Reply with quote  
    Advertisement
 
PostPosted: Apr 10th, '14, 03:20 
Xtreme Contributor
Xtreme Contributor

Joined: Mar 31st, '14, 14:43
Posts: 103
Gender: Male
Are you human?: yes
Location: us California
So ironic that in my fish tanks duck weed was considered a invasive plant and now I desire the growth for a sustainable fish food. It's easy easy easy to grow just get a tank or tub fill it with 5 goldfish and put duck weed in there it to thrive

Sent from my SPH-L900 using Tapatalk


Top
 Profile  
Reply with quote  
PostPosted: Apr 10th, '14, 03:25 
Xtreme Contributor
Xtreme Contributor
User avatar

Joined: Nov 21st, '13, 13:00
Posts: 225
Gender: Male
Are you human?: Yes
Location: USA / Florida
Now to get it done. On my list of things to do.


Sent from my iPhone using Tapatalk


Top
 Profile  
Reply with quote  
PostPosted: Apr 10th, '14, 09:29 
A posting God
A posting God

Joined: Jul 29th, '13, 07:58
Posts: 3382
Gender: Male
Are you human?: yes
Location: West Florida, USA
Sleepe, that was an interesting article. Hard to believe that fish raised in sewage water were then sold as food (after a 2 week purge). I guess I won't worry about an occasional bit of Neem oil in my system anymore. lol


Top
 Profile  
Reply with quote  
PostPosted: Apr 10th, '14, 15:18 
A posting God
A posting God

Joined: Sep 15th, '07, 09:09
Posts: 3712
Location: WA
Gender: Male
This was the bit that caught my interest (well and the DO levels). :)

"The reduction of total suspended solids (TSS) to the
extent of 53 and 37% through duckweed and fish ponds
respectively is attributable to their entrapment by the root
structure and removal along with harvested duckweed
biomass (Fig. 4; Table 1), besides accumulation at the
bottom. Van der Steen et al. (1999) reported better removal
of suspended solids in duckweed-based system due to
suppression of algal growth"


Top
 Profile  
Reply with quote  
PostPosted: Apr 10th, '14, 16:52 
A posting God
A posting God

Joined: Nov 10th, '12, 09:27
Posts: 2667
Gender: Male
Are you human?: maybe
Location: Vic
until they lose thier roots/die and become tank litter themselves. :P

Azolla is even worse for this.


Top
 Profile  
Reply with quote  
PostPosted: Apr 10th, '14, 19:30 
A posting God
A posting God

Joined: Jul 29th, '13, 07:58
Posts: 3382
Gender: Male
Are you human?: yes
Location: West Florida, USA
If I understand correctly, most people grow duckweed in separate tanks, not in an FT. This makes sense to me. Shallow basins(kiddie pools is what I'm thinking) and then be able to harvest to supplement food.


Top
 Profile  
Reply with quote  
PostPosted: Apr 19th, '14, 13:37 
Seriously, this cant be healthy.
Seriously, this cant be healthy.
User avatar

Joined: Mar 26th, '10, 20:46
Posts: 5404
Location: South Australia
Gender: Male
Are you human?: Yep
Location: South Australia
MartinC wrote:
Hi Binky, I found it! :D

A couple of things to be aware of:

1. Duckweed needs strong sunlight, and can grow very fast under those conditions.

2. Duckweed does actually consume ammonia directly so if your system is light on nutrients it could put a strain on your plant growth if you have the same water flowing through your duckweed bed and your grow beds.

3. One concern: haven't seen anyone on this forum grow duckweed long term. This to me is a sign it may not be as practical as it seems. It would be great to have someone grow it and give feedback as to growth rates and harvest information that turned into fish feed. (I may also have not seen threads with extensive duckweed growth on it.)

4. If you gather duckweed locally please quarantine it for weeks or months. You don't know what pathogens or pests you would be exposing your AP system to if you just hook it straight into your system. This actually goes for all fish and nursery bought plants too.

Regards, Martin.


I've been growing duckweed for a few years.

I'v grown it in almost stagnant water, and in high flow water with water splashing directly onto it so it gets submerged a foot deep where the water hits before rising back to the surface.

Attachment:
120 Things in 20 years - Aquaponics -Duckweed 02 BYAP sm.JPG
120 Things in 20 years - Aquaponics -Duckweed 02 BYAP sm.JPG [ 484.53 KiB | Viewed 6871 times ]


It definitely prefers not to be submerged, but still thrives here. I grew it in my topup water tank (left sitting for dechlorination) and almost killed it by adding a bit much acid (it went white), so pH might be a factor. My system runs at around pH 7.5 and I can grow half a 10L bucket full a month from the surface of a 500L round sump (water temp is currently 21c)

It also grows in a foot deep of water at the in the bottom of a wheely bin so its getting zero direct sunlight down there, but grows very slowly.

There are a few weeds that are sold locally here in plant stores as duckweed and are actually illegal to sell. They are larger of leaf, and have frilly edges and sometimes a touch of purple. So in Australia at least there's a fair chance some of the fails are due to it not actually being duckweed that people are trying.

Duckweed has a bit of a bad reputation for choking waterways because it grows so quickly, so make sure it doesn't escape to anywhere it doesn't belong.

Real duckweed looks like this...

Image

There are a few other varieties that you can see on wikipedia

I'll empty my tank of it and do a time lapse over a month or so so you can see the growth rate. (it's getting into winter here so wont be as spectacular as it might have been a few months ago. ).


one day I'lll get around to making this...

http://120thingsin20years.blogspot.com. ... eeder.html


Top
 Profile  
Reply with quote  
PostPosted: Apr 22nd, '14, 19:59 
Xtreme Contributor
Xtreme Contributor
User avatar

Joined: Nov 21st, '13, 13:00
Posts: 225
Gender: Male
Are you human?: Yes
Location: USA / Florida
Got my table built. It's the top half of an IBC cage with the bottom 8" of the tote. I took the retainer bars off two other tanks and am using them as the supports for the tank. Will more than likely put a piece of 1/2" plywood between the supports and the tank to prevent bowing from weight.

Now to figure out how exactly I want it to sit over my 3rd FT. Will take pics tonight.


Sent from my iPhone using Tapatalk


Top
 Profile  
Reply with quote  
PostPosted: Apr 23rd, '14, 09:52 
Xtreme Contributor
Xtreme Contributor
User avatar

Joined: Nov 21st, '13, 13:00
Posts: 225
Gender: Male
Are you human?: Yes
Location: USA / Florida
Pictures as promised.
ImageImage


Sent from my iPhone using Tapatalk


Top
 Profile  
Reply with quote  
PostPosted: Apr 23rd, '14, 19:28 
Legend Member
Legend Member
User avatar

Joined: Jun 22nd, '11, 17:01
Posts: 527
Gender: Male
Location: Central West NSW
How do you guys do your drains on your duckweed tanks (assuming they are inline/flow through)? I've found duckweed tends to clog drains quite easily but I'm probably doing it wrong


Top
 Profile  
Reply with quote  
PostPosted: Apr 23rd, '14, 21:23 
Xtreme Contributor
Xtreme Contributor
User avatar

Joined: Nov 21st, '13, 13:00
Posts: 225
Gender: Male
Are you human?: Yes
Location: USA / Florida
I'm interested too I'm still figuring it out.


Sent from my iPhone using Tapatalk


Top
 Profile  
Reply with quote  
PostPosted: Apr 24th, '14, 01:36 
Bordering on Legend
Bordering on Legend

Joined: Nov 22nd, '11, 03:31
Posts: 347
Gender: Male
Are you human?: Predominantly
Location: Dallas area, Texas, USA
This might not be too helpful, but I grow duckweed in barrels and buckets, and in an old child's plastic wading pool. Since I seem to be prone to the occasional stupid self-inflicted disaster, I've recently been growing a backup supply in coffee cups and plastic "To Go" containers on my desk at work, in case I need to re-inoculate my system some point in the future.

Here's a shot of part of my "work" crop:

Attachment:
Duckweed_Desk_sm.jpg
Duckweed_Desk_sm.jpg [ 398.84 KiB | Viewed 6806 times ]


Top
 Profile  
Reply with quote  
PostPosted: Apr 24th, '14, 07:23 
Valued Contributor
Valued Contributor

Joined: Feb 20th, '13, 10:23
Posts: 51
Location: South Florida, USA
Gender: Female
Are you human?: Yes
Location: Davie Florida USA
I try hard not to grow duckweed. It comes into our systems when we top off from the lake on the property. It gets all in the DWC rafts beds and it's like trying to get rid of roaches. I skim it out and feed it to the fish but it just comes back again and gets all on the rafts. The plants in the rafts don't like the duckweed sticking to them UGH


Top
 Profile  
Reply with quote  
PostPosted: Apr 24th, '14, 09:00 
Legend Member
Legend Member

Joined: May 15th, '13, 04:38
Posts: 508
Gender: Male
Are you human?: Yes
Location: USA, Northern California, SF Bay Area
I can only imagine the strange looks you get around the office ;-}
Shelgeyr wrote:
Since I seem to be prone to the occasional stupid self-inflicted disaster, I've recently been growing a backup supply in coffee cups and plastic "To Go" containers on my desk at work, in case I need to re-inoculate my system some point in the future.


Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 57 posts ]  Go to page Previous  1, 2, 3, 4  Next

All times are UTC + 8 hours


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
cron

Powered by phpBB® Forum Software © phpBB Group
Portal by phpBB3 Portal © phpBB Türkiye
[ Time : 0.065s | 15 Queries | GZIP : Off ]