Making your own seaweed extract.

[Harold Sukhbir]

Hi friends just wanted to say i'm thoroughly enjoying all the discussions on the Aquaponic Gardening site.I'm fortunate to be resident on a small island in the Caribbean with an abundance of seaweed that comes ashore..I've got some mixed messages on the net about the manufacture of seaweed extract and was wondering if anyone has any additional information on the subject. I am almost ready to commission a small aquaponic system, (taking forever to deliver an imported a water test kit.), and thought i would use the time available to prepare some concoction in advance, to help with and to maintain plant growth after cycling.

Best Regards

[George T]

You might try composting the seaweed, along with anything else you have on hand, then make compost tea. Aerate the tea for 48-72 hours. For info, research AACT (actively aerated compost tea). Regards. GT

3. Brew. Filled a 5 gallon container with a tight seal 3/4 with seaweed and the rest with water and about 1/2 cup of molasses.Mix and aerate for a minute each day.This brew will have to "cure" for approx. 4 months.It depletes nitrogen if applied before the curing process.

[Harold Sukhbir]

I've also tried this without any aeration,seems to work well. If i had to choose though, i think No. 3 works best.

George J. Thurmon said:

You might try composting the seaweed, along with anything else you have on hand, then make compost tea. Aerate the tea for 48-72 hours. For info, research AACT (actively aerated compost tea). Regards. GT

3. Brew. Filled a 5 gallon container with a tight seal 3/4 with seaweed and the rest with water and about 1/2 cup of molasses.Mix and aerate for a minute each day.This brew will have to "cure" for approx. 4 months.It depletes nitrogen if applied before the curing process.

[Michelle Silva]

Wow, this is great ,thanks.

[Homefire]

Thanks for that tip Harold.  I've just begun to cycle up my new system after winter pause.

I made some aerated compost tea with worm poop, kelp, molasses and yard compost.  What a chemistry experiment!  When i put it in the pot it smelled like cow manure; anaerobic.  After i put in an air stone and perked it 24 hrs. it smelled minty, sweet.  I put some in the grow bed. Perhaps i got ahead of myself there.  I just now noticed that it's supposed to cure.

 

Homefire

[Harold Sukhbir]

Hi Homefire,

What a mixture! sounds great to me, let me know how it works. The recipe to cure for a 6 month period is mostly done when you have large quantities of ingredients available and don't want the unused brew to go to waste, so cure it and store it for later. I've used the fresh brew also and they work almost the same. You know it's cured when you get a white fungus looking film on the top.

Homefire said:

Thanks for that tip Harold.  I've just begun to cycle up my new system after winter pause.

I made some aerated compost tea with worm poop, kelp, molasses and yard compost.  What a chemistry experiment!  When i put it in the pot it smelled like cow manure; anaerobic.  After i put in an air stone and perked it 24 hrs. it smelled minty, sweet.  I put some in the grow bed. Perhaps i got ahead of myself there.  I just now noticed that it's supposed to cure.

 

Homefire

[George T]

The reason for brewing compost tea with an aerator and adding a stimulant such as molasses  is to multiply the bacteria.  Once the small amount of food is consumed, the bacteria begin to die - after about 72 hours (much sooner without aeration).

 

What would you expect to happen when you cure it for 6 months?

Harold Sukhbir said:

Hi Homefire,

What a mixture! sounds great to me, let me know how it works. The recipe to cure for a 6 month period is mostly done when you have large quantities of ingredients available and don't want the unused brew to go to waste, so cure it and store it for later. I've used the fresh brew also and they work almost the same. You know it's cured when you get a white fungus looking film on the top.

Homefire said:

Thanks for that tip Harold.  I've just begun to cycle up my new system after winter pause.

I made some aerated compost tea with worm poop, kelp, molasses and yard compost.  What a chemistry experiment!  When i put it in the pot it smelled like cow manure; anaerobic.  After i put in an air stone and perked it 24 hrs. it smelled minty, sweet.  I put some in the grow bed. Perhaps i got ahead of myself there.  I just now noticed that it's supposed to cure.

 

Homefire

[TCLynx]

I would think the aerated tea should be used immediately before the bacteria begin to die.  Most people use the aerated compost tea because they are trying to expand the beneficial bacteria populations in their garden.  So if you are hoping that compost tea will boost cycling, then you definitely want to use it very fresh.

[Francois Lemmer]

 

Thanks for this info Harold good to know...i will store in the back of my head....

Harold Sukhbir said:

For those who might want to make their own seaweed extract.I have tried three methods to prepare the liquid.

1. Sun dry.Spread it loosely on the floor in the sun.The seaweed dries up in a couple of hours to a dark brown color.This can be mixed with water ( i used about a 20 water to 1 dried seaweed ) to make a tea.

2. Juiced. Fresh seaweed in a juice extractor with water.This was 40 water to 1 seaweed. This has to be refrigerated unless you add some preservative.

3. Brew. Filled a 5 gallon container with a tight seal 3/4 with seaweed and the rest with water and about 1/2 cup of molasses.Mix and aerate for a minute each day.This brew will have to "cure" for approx. 4 months.It depletes nitrogen if applied before the curing process.

The first 2 work just as well as each other.Threw away some of the juiced solids in my garden and noticed great improvement with the surrounding plants! I'll update this post when i finally try the brew.

[Harold Sukhbir]

Hi George,

Seaweed has so many" beneficial's", trace and macro elements and fatty acids need by plants,as a result the extract is used mostly during cycling in AP.There are commercial products that offer cured seaweed extract for this purpose. Fresh seaweed has nitrogen depleting bacteria(to create bio-avalibility) which is not ideal for a newly cycling system. Since the object of adding extract is to provide all necessary nutrient for plant growth and to aid cycling it may be preferable to use the cured extract as we don't really want to diminish the establishment of the nitrogen cycle in our systems, but this is only my opinion.

About once every month i add some to my system to ensure adequate nutrient balance and as it is already cured it won't destabilize my AP "engine". I think it's better to add this more or less "complete" nutrient source than the manufactured ones to avoid over-compensating or under-compensating by the human controller.

[Shas Cho]

TCLynx said:

...Just keep the salt levels low enough that your plants stay happy.

  

That's good advice, but...

how low is that?

Is there a consensus on the optimal salt level

in a tilapia-based aquaponics garden?