brine shrimp refugium/perpetual plankton producer

[dave willmore]

Hello folks,

I'm building a tank that wraps around the perimeter of my sunroom designed to keep plankton alive for a full natural life until eaten by polyps or filter feeders. There are no skimmers or fast (1720 rpm) water pumps.

Instead a settlement chamber removes detritus. Heavy waste drops to the bottom of the chamber where solenoids flush it down to a 1,000 gallon brine shrimp refugium below. Brine shrimp will recycle the fish poop into millions of live plankters.

Brine shrimp are non-selective filter feeders and ingest everything smaller than 60 microns. They are great detrivores. Inside the sump refugium, detritus drops into a screened chamber with 70 micron openings and a pump on the bottom periodically grinds up detritus and puts it into the water column.

I plan on a low density continuous culture (maybe 200 brine shrimp per gallon. Batch cultures are up to a hundred times that dense). Females produce up to 75 nauplii per day under ideal conditions. Even if they only produce 20/day, 200,000 adults produce 2 million baby brine shrimp each day for the display tank.

To concentrate nauplii between two screens, an outside large one is sized to let in nauplii but exclude large adults, and an inside small one is sized to let water flow through but trap nauplii. Inside this area a pump periodically sends nauplii to the display tank.

Probably much of the nauplii will be delivered at night when polyps are open. Because the display tank circulates without harming plankton any BBS not consumed by corals will be available at first light for the planktivore fish.

A food loop is made where brine shrimp consume waste and produce plankters so I hope to greatly reduce or eliminate food, yet still keep planktivores and corals happy. The brine shrimp refugium will probably trend toward higher nutrient levels for which they are well suited. With the BS fuge trending toward higher nutrient levels the display tank will trend toward lower nutrient levels, especially if food is not needed. BS fecal pellets will be pumped into an algae refugium which is part of the system. But even if brine shrimp convert only half the poop to plankton, that cuts the algae fuge's work by half.

The sump is sunk into the earth so cool water can help with dissolved oxygen levels. The transfer of concentrated nauplii water to the display tank should only be 20 or 40 gallons per day, less than 1% of the display volume.

Please help me with criticism and suggestions while I am building the system. It will be a much better system and changes will be a lot easier now than after it is built.

Thank you very much for your help. I can post pictures if my narrative isn't clear enough.

 

[TheFishMan65]

I think I am following, but I also admit the process is probably a little beyond my experience. But the main tank is 2000-4000 gallons? Oh read a little further: 3,500 gal under construction.

If the brine will eat anything, then why add poop just to support algae?

Picture would definitely help. And when you get this build I want to come see it. Need help?

 

[dave willmore]

I think I am following, but I also admit the process is probably a little beyond my experience. But the main tank is 2000-4000 gallons? Oh read a little further: 3,500 gal under construction.

If the brine will eat anything, then why add poop just to support algae?

Picture would definitely help. And when you get this build I want to come see it. Need help?

The Fish Man, thanks for trying to see a clear picture through my long narrative. To keep the post on point I left out the algae refugium. Two million BBS will feed planktivores but I'd like a dozen pygmy angel harems to eat filamentous algae screens from the algae refugium. Algae growth in combination with brine shrimp conversion is intended to recycle waste into quality food.

I won't add poop just to support algae. Whether the brine shrimp convert the 10% or 90% of detritus into babies remains to be seen, but algae will need to "polish up" the remainder. Brine shrimp do eat anything, even their own poop (after a couple day's conversion into bacteria), but if shrimp convert 50% of detritus into zooplankton their fecal pellets need the sunlit 500 gallon algae refugium to absorb what's left. With luck, I stop adding food to the tank and water quality issues disappear, but I am not that lucky.

If brine shrimp are efficient enough to convert most of the detritus into BBS, then I add more planktivores until the system balances. I have no clue if equilibrium happens at 200,000 adult brine shrimp and 30 planktivores, or a million brine shrimp and a shoal of 300 planktivores.

But wouldn't it be fun to find out? If corals eat half the BBS and each fairy wrasse and anthia needs 2,000 BBS per day, the tank would support 500 planktivores. I won't get this many but I like the idea of pulsing zooplankton through the tank on a 24 hour basis like the natural reef because I think panktivores prefer many small live meals to a few large dead ones.

And even if perfect balance and 100% recycling never occurs (which it won't)I think a tank close to equilibrium is a lot less work.

The tank frame is welded but not yet fiberglassed. I am now welding shelves for the phyto cylinders. I would enjoy your help and advice very much.

 

[WingoLED]

Interesting project, keep us updated.

Incidentally, I am thinking about building an FW roti pool attached to a pond. Your project could yield some pointers to my project too.

Have you considered how to remove the BS shell-from the same first screen that filter adult BS?

 

[dave willmore]

Interesting project, keep us updated.

Incidentally, I am thinking about building an FW roti pool attached to a pond. Your project could yield some pointers to my project too.

Have you considered how to remove the BS shell-from the same first screen that filter adult BS?

There shouldn't be any shells/cysts produced under regular brine shrimp culture conditions. I think I remember reading that shells are produced only in the fall when water cools and food levels drop. This is good for several reasons -- no cysts to foul the water or larvae stomachs, and it takes far less energy for the artemia mommy to make live babies. If you live in a warm climate your FW roti pool may work year round. Many have grown rotifers on vegetable juice so phyto probably isn't necessary for you, which is a good thing because phyto takes a lot of work. Rotifers can do well on many different diets. I always thought that juicing leafy greens from the garden would keep rotifers well.

 

[Supernova26]

This is is going to be nice if it works correctly. The first difficulty I see is keeping the screens clean so the napuli can flow correctly. Good luck

 

[Opcn]

BBS are phototaxic as I recall, are ABS as well? If not then you can draw the BBS towards the screens with out any significant flows of detritus joining them, but if adults are too then you can expect this to clog the screens with adults.

I really hope you keep us updated as you go I'm very excited to hear about this project.

 

[dave willmore]

This is is going to be nice if it works correctly. The first difficulty I see is keeping the screens clean so the napuli can flow correctly. Good luck

You're absolutely right. The screen may need a large surface area. If the BBS removal isn't efficient then the 200,000 adults will be joined by a million growing mid stage instars creating a high culture which will soon crash. But that problem can be solved by hand netting. It will take some experience to hand net enough to keep the culture stable.

 

[dave willmore]

You're absolutely right. The screen may need a large surface area. If the BBS removal isn't efficient then the 200,000 adults will be joined by a million growing mid stage instars creating a high culture which will soon crash. But that problem can be solved by hand netting. It will take some experience to hand net enough to keep the culture stable.

I meant to write high DENSITY culture. A high culture would have its own problems! An airlft would drive water flow pretty effectively and can be adjusted to keep adults from getting trapped on the screen, but an inefficient BBS concentrator would lead to overstocking of the BS refugium. hand netting a few ounces of midsize shrimp would be fun once a day, but I'd rather have an automatic system.

 

[Blackice55]

I would really like to see pics or a diagram.

 

[dave willmore]

I would really like to see pics or a diagram.

Blackice55, I don't have that kind of computer talent but I have pics of the framed tank. It is really just a shrimp reactor with an input of fish poop and an output of BBS.

The key is balance. I would hope that 500 fish and corals produce 15 pounds of waste each day and 1,000 gallons of BS eat that to produce 15 pounds of babies each day. If the shrimp can't do the whole job, 500 gallons of algae, sponge and xenia refugium help out.

I can promise that perfect equilibrium will not be achieved. But if 90% of the food is self-generated, I can also promise that 90% of the water quality issues disappear.

Plus a plankton based system will be lots of fun. I'd like to see how a bunch of pygmy angel harems react to each other and I'd like to see how a really large shoal of planktivore fish will behave when well fed. 3,500 gallons of constant live food presents a unique opportunity to see how corals grow also. I will work on some pics for you.

 

[dave willmore]

Another thought on converting fish poop into brine shrimp food. The fish poop will drop into a funnel shaped screen with a one gallon bucket at the bottom. A sump pump in the bucket will turn on for one minute as often as the timer permits and will grind up and spew out the detritus. The water flow in the shrimp tank will sweep out any particles smaller than 70 microns that go through the funnell screen, while larger particles will fall down the screen to the bottom to repeat the cycle. Think this will work?

 

[xboxdisc]

How would you channel the BBS back to the display tank without harming them?

I'm not sure, but having the sump pump grind up large pieces of detritus may shorten the pump's lifespan. Pumps are expensive too.

 

[TheFishMan65]

I think the plan was air lifts to get the BBS back.
I think he was going to use a true sump pump that should be a little more robust.

 

[dave willmore]

How would you channel the BBS back to the display tank without harming them?

This is a great question xboxdisc, if you follow the goal of keeping plankton alive and deduced that there isn't a lot of water pumped from the sump to the tank. I could use a diaphragm pump, Jabsco makes one for about $300 (model #66000 or something like that). I could also use an impeller pump knowing that it will kill 10 to 20% of the BBS which will be quickly consumed anyway. I don't have a better solution so far, can you think of one?

 

[spieszak]

You could try to work out something to gravity feed the bbs... Set it up like one of those water fall things that tips when its full. So two containers, one lit that the bbs will naturally swim too, that drips into a container that tips when full. Kinda out there, and I haven't thought it through, but....

 

[dave willmore]

You could try to work out something to gravity feed the bbs... Set it up like one of those water fall things that tips when its full. So two containers, one lit that the bbs will naturally swim too, that drips into a container that tips when full. Kinda out there, and I haven't thought it through, but....

If a refugium is above the display tank this is a great solution because the zooplankton flow down to the fish without going through the blender (pump). I think we should try for this arrangement whenever possible.

However my refugium is beneath the tank. It takes less electricity for me to lift 30 gallons of BBS per day (at 8 pounds per gallon that's 240 lbs x 4 feet of head equals 1,000 foot pounds) up to the display tank than to cycle the display tank through the sump twice per hour for this distance (3,000 gallons at 8 lbs per gallon is 24,000 lbs x 4 feet of head x 2 cycles x 24 hours is 4.6 million foot pounds if my math is correct). In a large system the energy to move water becomes more of a factor than in small systems so I have to look for short cuts.

But keep those creative ideas coming, your idea to locate the refugium above the tank is a good one.

 

[dave willmore]

I'm not sure, but having the sump pump grind up large pieces of detritus may shorten the pump's lifespan. Pumps are expensive too.

Fishman65 has seen the tank and gave me some great advice to scrap the solenoids in favor of a true sump pump. He pointed out that a solenoid would fail to close on some type of particulate and then drain the tank. A sump pump should grind detritus pretty well and even handle things like sand, I hope.

 

[dave willmore]

Because brine shrimp eat everything smaller than 70 microns a sump pump will grind fish poop into shrimp food particles. A sump pump in the display tank at the bottom of the settlement chamber will remove detritus to the brine shrimp refugium.

At first my idea was to have sump pumps in the refugium at the bottom of a 70 micron screen funnel continually grind detritus down to edible size. But it was pointed out that the screens could easily clog.

So what do you think of a different model. In the conical shrimp refugium a timer simultaneously turns off the aeration and turns on a light. Artemia gather at the surface for oxygen and because they are attracted to light. Then ten minutes later sump pumps at the bottom of the cone turn on for a few minutes and spew ground detritus into the water column. A few minutes later the sump pumps turn off, the light turns out and aeration starts again. Hopefully very few artemia will be near enough the bottom of the refugium to be ground up with the fecal pellets into smaller bits of shrimp food.

Do you think this would work? The brine shrimp refugium is about 42" deep, a little over a meter. I envision this cycle taking place every half hour or hour.

 

[mussel and hate]

Subscribed, I admire your ambition and I really want to see how this project turns out.

Feeding would be simplified if the culture tank were above the DT. You could still have the settling chamber/sump beneath the DT with the culture tank feed pump as a macerator for detritus. I'm thinking a series of 24" laundry tubs with drains to a manifold to the pump.

Since you're welding stands your probably way past the point where my comments are realistic so I have a suggestion for a BBS safe feed pump. You could probably DIY up a water wheel with a low rpm electric motor and some PVC. You'd get a bonus surge with each BBS dump.