Saltwater Green Water Culture

  • #1
Hi! So I'm trying to work out green water culture for saltwater. I have freshwater green water cultures that I use to feed my Daphnia cultures (moina and magna), but I kinda want to raise brine shrimp as well.

Like with both my moina and magna cultures, I started trying to raise brine shrimp with spirulina and chlorella algae in powdered form. I started with a very small qty of the brine shrimp and feed about a pinch of the powder every day. The first colony crashed. I tried feeding every other day to see if it was the food, and that crashed faster. It's similar to when I started my moina and magna cultures, but when I was able to successfully get green water for my moina and magna cultures, they started thriving. My moina and magna cultures are in outdoor tubs with no aeration esp since the starters came from literally a small undeveloped water area (it's too big to be a puddle but it's also not a lake if that makes sense; there are wild fish in it, too) near our house, but the brine shrimp will be in an indoor tank for easy access to feed my adult fish so it'll have an air pump hooked onto a sponge filter.

I got my first healthy green water culture by mixing 1 tablespoon fertilizer and the water I got from washing rice, dumped that in a gallon of tank water I accumulated from water changes, and leaving it out in the sun with an air pump for less than two weeks. If I mixed tank water with salt, then added the fertilizer and rice wash, will I get the same results and get saltwater green water? I'm assuming I can't dump freshwater green water starter in saltwater and expect it to not die, so I'm considering starting from 0.

I tried asking around locally if someone is selling saltwater starters, but I didn't get any leads in my area since my area is still under quarantine. This is technically my first saltwater tank, so I'd appreciate tips as well!
  • #2
I don’t have many answers, but have a bit of experience. I am of the just do it an see what you get school of thought.

I have green water that I have actually been raising tiny fry in small tanks of just green water.

Let me start with something I know for sure.
Brine shrimp need more than sea salt sold for cooking to live past 5 days. I have been told to use marine sea salt sold for marine tanks in order to grow out brine shrimp.

i have in the past had similar experiences trying to grow brine shrimp past 10 days using yeast unsuccessfully. Why not just put jars of marine salt water in the sun with a nutrient as the starter.

I watch this recently . It’s a long way from one measured teaspoon of fertiliser. But this is the path I think you need to walk to find a salt water green water.

I like your idea and have in mined to try it myself as the yeast was unsuccessful.

I am sure you have seen this?



  • AF95477C-5627-4333-AD4A-D84ED53AE67C.png
    342.1 KB · Views: 48
  • Thread Starter
  • #3
Thanks for this! I have been using API Aquarium Salt, which as far as I know is pretty different from marine salt. I think I’ll pick up some marine salt before I start culturing. Thanks for this!

I have watched both videos you’ve linked, and every time I see this video of Sir Dexter (he’s from my country and he’s responded to my inquiries once or twice on his channel), I still get shocked that he uses manure. It makes sense, though! I’m in an urban area and manure isn’t available to me, so I was told to use 14-14-14 fertilizer, 46-0-0 Urea, and Rice Bran. It looks to be similar to manure, probably more potassium. Unfortunately, because I’m in quarantine, I only had 14-14-14 fertilizer on hand that I use for my house plants and to help start my Moringa and Mulberry cuttings.

What I did as a nitrogen source to replace Urea was use high nitrate tank water. I had setup 2 new 5 gallon tanks to prepare for the breeders of a new strain of guppies I’ve been meaning to work on. I had 80+ ppm Nitrates when Ammonia and Nitrite read 0, so instead of throwing that out I decided to put half a gallon of it in a transparent container, half a gallon of dechlorinated tap water, 1 tablespoon of fertilizer. Then, because I sometimes watered my plants with rice wash, I decided that maybe I can use that as an alternative for using rice bran. I left it out under the sun with one of those usb air pumps.

The water turned emerald green in almost 2 weeks. I didn’t throw out the high nitrate water since my logic was if this works, I’d probably do good to have this on hand for another batch. I took 1 liter from the already green water as a start culture, added about 1.5 to almost 2 gallons of dechlorinated water, then used the 1 liter as a starter for 2 new containers with the procedure I know works. Now I have three 2.5 gallon containers of emerald green water that I use to feed my daphnia cultures, I have 2 of the magna and 3 of the moina daphnia going and I feed them around every 3 days and harvest every day. Green water has honestly made all the difference for me. I haven’t restarted the green water, I just top up with the water from my water changes.

Anyway, thanks for the tip! I’m going to get marine salt delivered and try the same method. I might try using my freshwater culture as a starter just to see if that does anything. I’ll probably update this thread with my experiment at some point.
  • #4
I don't think you can culture brine shrimp. The eggs need a continuous tumble to hatch. That's why we us air in a bottle. I guess if you use air to keep water moving you might be able to get multiple generations. For saltwater you want to culture copepods. They will reproduce in green water.
  • #5
Hey Rcslade124,
Up until recently I would have agreed with you about brine shrimp needing to tumble to hatch because that’s how all the hatcheries work right?

This model in the link has been around for a few years but it’s still going to cost a fortune to get one into Australia.

Hobby Artemia Hatchery

In terms of having them reproduce in their own tank it’s quite possibly. Check out the link above to marks U tube channel .
  • Thread Starter
  • #6
Just an update, I slowly introduced salt in a batch of freshwater green water and that failed. I'm gonna try again and rule out over fertilizing. I'm still waiting for the other one to get green.

I've watched more videos and stumbled upon this video from someone in my country:

Interestingly, I'm actually part of a spirulina sharing and growing group and have been for years because I was interested in growing it for my shrimp. I realized that Moringa and Mulberry trees will benefit me and the shrimp more, and that if I needed IAL, there is a tree near our house. They use a similar method to cultivate green water, and I've connected with someone who can send me a live culture of spirulina for free. Live spirulina potentially would be a better culture for daphnia and gutload them with that as well so I'll probably start another test with that.

Here is another one using another kind of method without salty green water, just using algae he scrapes outside which I assume isn't a saltwater variety of algae.

Similar Aquarium Threads

  • Locked


Top Bottom