Dave W's 3000 gal plankton/reef tank

[dave w]

 

Here is a pic of the subfloor. The 36 water lines are in, the wire is mostly run to the sumps, the sheet of plywood was used to square up the floor and set the slope to the center floor drain. The pex tubing under the floor for radiant heat goes in today. The pex lines to heat the tank in winter will go under the 2x4's, creating little heat pockets that may be effective in keeping the water warm during February cold snaps. Thanks for the suggestion to heat the tank with pex hot water lines from my house water heaters. I will also run additional pex lines for the geothermal heat pump and take a pic of that also.

[zygote2k]

Holy confusion, Batman!

I hope there isn't any leaks....

[Chad]

Wow

 

How will you clean the sumps when the tank is sitting on top?

[dave w]

Holy confusion, Batman!

I hope there isn't any leaks....

 

I'm really not worried about the 1/2" PVC water lines leaking, and if one does, there are 18 to spare. It just looks confusing, I labelled all the pipe ends so I know what goes where.

[dave w]

Wow

 

How will you clean the sumps when the tank is sitting on top?

 

I have about 14" of height clearance at the front of the sumps into which I can squeeze my body, and the glass sump doors will be from 22" to 26" wide. It will be a good incentive to keep my weight down, although I may need a mechanical creeper (for sliding under cars) for the "belly work". Each conical shaped sump bottom has been dug down into a trench, so the deep part in the middle (near enough to the front to reach) is about 24" lower than the sides. When I drape PVC pond liner into these, I hope there is enough slope that fecal pellets from copepods or artemia fall to the bottom of the cone. I will put a PVC frame in the sumps to act as kind of a bracket with 1.5" vertical pipes in the corners to bubble air through for circulation, and a slotted bottom pipe will run along the bottom trench to collect fecal pellets.

 

Changing the screen that surrounds the bottom pipe may require a contortionist, but flexible tubing that is weighed down to the bottom may be easy to work with. I also anticipate vacuuming up the bottom trench with a pipe connected to the inlet of a small pump with the outlet tubing pushed into the 1" surface drain on each sump. Vacuuming the bottom should hopefully only lose a few gallons of water per day.

 

Finally, while my philosophy is to try and remove the skimmer from the main tank, this does not extend to the live food in the sumps. Copepods need higher quality water than artemia or rotifers, so I have plumbed all the sumps to the pump area so skimmers can remove the fecal pellets drawn from the bottom of the sumps.

 

Now that I've dug the sumps into cones, the sump area is more like 3,500 gallons than the 2,000 gallons it was before. But I hear that a batch of pygmy angels need a couple thousand gallons of copepod cultures to bring them through. While I guess this number is high, there's no doubt that copepods reproduce slowly and they need lots of algae to keep them going.

[dave w]

Here are some more pics.

 

 

This picture of the western half of the tank shows the supporting joists cut to length and the attachment of the concrete board which will be one of three layers of material on the bottom of the tank.

[dave w]

Here is a picture of half the tank with the concrete board bottom in place. I've made a couple more changes, first I think I'll bury the pex hot water pipes directly in the sand. There won't be any rocks on top to become instable and they should hide well under the fiberglass structure. Second, I've gone back (again!) to a tidal system that reverses flow every 6 hours. My helper is in the picture to give a sense of scale. For summer cooling I think I'll bury cold pex lines under the sand in the shallow part of the refugium. If you look carefully at the subfloor you can make out the red tubing that will heat the floor of the room.

 

[dave w]

For those who have trouble getting to sleep, this pic is of the floor drain in the middle of the room and most of it will be under the sofa. Each side of the room will drain down to this channel so I can clean up spills or wash everything down with a garden hose.

 

[dave w]

Another thought to add. As the pics show, the front to back measurement of the tank is 6 or 7 feet in the corners. I think this is enough depth to build a grotto in each corner with a ribbon of white sand leading the eye back while a cascade of corals come down each side of the valley to the bottom. Hopefully the sway of sea fans and gorgonians with Chad's wavemaker will complete the effect.

[dave w]

I've been framed! Here is a pic of the east side of the tank with the stainless frame held in place with clamps.

[dave w]

here is a pic of the west side of the tank.

 

[Coral Hind]

I have a question about the 2x4 joists going under the tank, what horizontal support will they be resting on? Outside edge looks like brick but what about the inside edge?

[dave w]

I have a question about the 2x4 joists going under the tank, what horizontal support will they be resting on? Outside edge looks like brick but what about the inside edge?

 

Coral Hind, you are very observant. While the outside edge rests on brick, the inside block couldn't rise up to the tank because I need 14" of room to access the sump through glass doors. So the inside edge of the tank rests on a 4x4 post every three or four feet. On top of this post is a stainless angle upon which the 2x4 joists rest, then a 2x4 facer (bandboard) ties together the ends of the joists. Finally a piece of stainless flat bar 1/8" by 3" is screwed into the bandboard all across the face. The combination of the angle, the bandboard and the steel plate on the face is what carries the load between the 4x4 posts. My longest span is about 23" between posts.

 

Hope that helps, and thanks for getting involved again. I missed your input because it appears to me that you really know what you're talking about. But I can be easily fooled.

[zygote2k]

looks good Dave.

[dave w]

looks good Dave.

 

Thanks. It took 6 months to get this far. Sometimes that seems like a lot, but considering that it has been squeezed between my work and family I wonder that it hasn't taken longer. You've always given me good advice on the design of the system, and it was your idea to move this from my basement to the sunroom. My wife thanks you for getting this out of the house.

[BowieReefer84]

How big on an RO/DI unit are you going to get?!?

[zygote2k]

After listening to Ret Talbot say that the next breakthrough is going to be the production of planktonic foods, i think your 3000g tank will be the perfect hatchery...

[dave w]

How big on an RO/DI unit are you going to get?!?

 

 

BowieReefer84,

 

I don't yet know an answer to this one. My well water is high in iron and I haven't checked it for nitrates or phosphates. I have two Costco RO units for my house that I have never hooked up. With over 1,000 gallons of shallow algae refugium under sunlight I hope nitrates and phosphates will be kept in check without RO water. Because I will recycle the refugium turf algae to feed a lot of tangs and pygmy angels, I hope I won't need a lot of outside food, also helping to keep nutrients low.

 

Having said all that, if algae problems persist in the main tank, I will buy the largest RO unit I can afford and a skimmer too. I'd like to see the system in operation for a few months to see if they will be necessary and to see how much daily evaporation I have.

 

Another factor is the tank cover, if I have fish jumping I will keep the cover tight to minimize evaporation, expecially in winter. If I find that the size and reef design prevent jumping I'd like to loosen the covers, especially in the summer. Loose summer covers let evaporation help with the cooling.

 

So it is a work in progress with no answer yet. I will let you know.

[dave w]

After listening to Ret Talbot say that the next breakthrough is going to be the production of planktonic foods, i think your 3000g tank will be the perfect hatchery...

 

Even if the experiment fails it will be a lot of fun. The more I read Sprung and Delbeek the more I see a dichotomy. The Berlin system grows great corals, but most reef organisms also have a huge demand for algal, zoo and bacterioplankton that are removed by skimmers. They say large systems develop a greenish hue as the ratio changes between polyps and open water in comparison to smaller tanks. I can only guess how much plankton can grow without a skimmer, I've read 100,000 plankters per gallon.

 

But excess plankton is really just my excuse for more filter feeders. I hope at some point the plankton and the polyps will balance with phytoplankton drips and the production of the refugium.

 

I also know it sounds crazy to put in 4,000 gallons of sumps, but I would like to culture 1500 gallons of copepods and 700 gallons of artemia. At high densities those cultures crash easily, and I hope lower density cultures can produce for a long time. I've always felt that live artemia from the store were empty shells of starved animals, their pink color comes from the stress of producing hemoglobin in low oxygen water. Pink may look pretty and be more marketable, but nutritious zooplankton are usually green and brown.

 

If I fail, just put me at the end of the long list of humbled people that couldn't breed flame angels.

[dave w]

Can anyone give advice regarding a permanent material to fill voids in the artificial reef? I am leaning toward hollow cavey tubes as the main structure of the reef with the outside parged with oyster shells/sand/cement/rock salt. The inside will be tubes and large fiberglassed areas that will stay hollow. I'm thinking of putting slow moving powerheads or propellers in these to create a vertical upwelling effect through some type of media.

 

I could put eggcrate a foot up to hold the material and need something in the space above to breed a lot of things to feed the tank. Can anyone suggest a porous or spongy material large enough for small critters to multiply? I'm not sure I should worry about anaerobic zones developing inside them, the powerheads can be cycled such that detritus may fall out the bottom when the power is turned off, or maybe the powerhead/propeller can be reversed on a cycle.

 

Loose rolls or coils of plastic screening come to mind, say with half inch spacing between the strands. This seems large enough to not trap detritus but small enough for amphipods and such to have lots of surface area to develop good densities. Again, with a large refugium I don't think I need the hidden reef hollows to be a denitrifying area. This area will be separate from the caves, of which I hope to build plenty.

 

Thanks in advance for the advice. I will be out of town for the next week but hope to weld the frame as soon as I get back.

[dave w]

Folks, now that the main tank frame is going up, I'm trying to automate the feeding of 100,000 baby brine shrimp (BBS) plankton to the tank daily. I have an unlit 5' section of the refugium for cryptic sponges which I will make into a cone for a settlement chamber. A solenoid at the bottom of the cone will periodically flush settled detritus to feed about 1,000 gallons of artemia in part of the sump below.

 

Suppose I flush 10 gallons of detritus down to the artemia sump per day to make baby brine shrimp. I will also need to pump 10 gallons of concentrated BBS back up as plankton. The BBS concentrator will be a fiberglass windowscreen bag (or screen wrapped around a holey bucket) sized to let BBS pass through but keep out larger shrimp. Inside the bag the airlift creating flow is screened by 53 micron screen to prevent BBS from going up the airlift. In the bucket is a pump timed to kick on every hour, thereby pumping 10 gallons a day of BBS plankton concentrate up to feed the display tank.

 

I'd like to automate this into a loop to minimize outside food input and resulting nutrient problems, because I hope to avoid skimming. Because the artemia sump is cone shaped the fecal pellets fall to one low point on the bottom. At this spot a pump will periodically send these pellets to the refugium. Algae and xenia of the 1,000 gallon refugium (under nearly 24 hr. lighting) should hopefully convert all these nutrients into fish food. This would close the nutrient loop (BBS feeds fish, fish poop drops to bottom of settlement chamber and feeds artemia, artemia propogate BBS to feed the main tank, artemia poop gets absorbed by refugium to create algae and xenia to feed non plankton eating fish).

 

The trick is in sizing and timing the pumps and solenoids to balance each other. Sprinkler timers are made to cycle solenoids up to 6 times per day for new lawns. If I needed to flush the settled detritus more than 6 times per day, I would put in several solenoid drains and several timers. I haven't set up electric timers for a few years, but assume that with all the different pump sizes out there and multiple timers set to the minute or to the second, a little experimental time could make this balance. While I am tuning Chad's piston wavemaker.

 

If this system doesn't completely balance the food loop, I could flush half the settled detritus or half the artemia poop down the drain for nutrient export. It will take some time to see if 1100 gallons of refugium will balance 2400 gallons of display fish.

 

Any criticism or suggestions to make this work better?

 

Thanks in advance.

Edited May 6, 2011 by dave w

[dave w]

My estimate of 100,000 BBS a day was just a guess. Now that I think about it, that's only 100 BBS per gallon per day, a very low figure. Healthy artemia produce up to 15 babies a day, and there will be far more than 66 female artemia per gallon, even in a low density system. More realisitc BBS plankton production might be more like half a million plankters per day.

[dave w]

Upon further thought, the above post creates a "brine shrimp refugium", whereby one dumps ten gallons of detritus in one end and out the other end comes ten gallons of BBS plankton. Now I know what to do with my large sump -- if too many fecal pellets degrade 1,000 gallons of artemia water quality, I need to increase the size of the brine shrimp refugium. I know it is tempting to call this a "BS refugium", but let us refrain.

 

One thing about artemia is that they grow on their own poop (after a couple day's cycling through bacteria). Bacteria break down the poop and then artemia eat the bacteria. So although artemia may only have an initial biomass conversion of maybe 5% (5% of food is turned into shrimp protein), each day they gain another 5% of weight from the food/poop/bacteria cycle. With a few weeks, this approaches complete food conversion to artemia biomass.

 

Artemia culture is fairly straightforward because they are among the world's hardiest creatures. Consider that while living in saltwater of 300 parts per thousand of salt, they still maintain only 9 parts per thousand of blood salinity. If there were a gold medal for osmoregulatory feats the world record would be permanently theirs. Early researchers put artemia in test tubes and then added incredibly high amounts of ammonia, acid, chlorine, sulfur (you name it) and were amazed that the shrimp could survive and thrive at levels far beyond any other organism.

 

Artemia basically need two things: adequate levels of dissolved oxygen and adequate levels of food (which are flip sides of the same coin because oxygen levels only tend to get out of whack if excess nutrients pollute the water). Other than pollution, the other oxygen factor is cool water which holds lots of oxygen where hot water holds none. The sumps buried 8' underground should hopefully maintain cool water and high oxygen.

 

So (in theory) one can replace expensive water quality equipment with a settlement chamber to flush detritus to the brine shrimp refugium which then creates plankton for the tank.

 

Actually it sounds so simple there has to be something wrong with it. Please help with comments and criticism. Tweaking ideas now will be easier than changing it after the settlement tank is built. Thanks.

[Jager]

dave my apologies for dropping off there, health got iffy and am still getting that all back together.

 

from what you are saying I think (and that may not be worth much as the prescriptions are good) you have the right idea. i have not read anything at least that disagrees with your approach on the settlement chambers and ssuch, that being said you may wish to email one of the big aquaculture companies about their systems or thoughts, as they do massive turnovers. I know greshemH on RC is/was affiliated with one group, and rodsreef is a big name in clownfish and food (if i am not mixing up the names)

 

as far as the material to put in your "caves" and hollow areas, if they are open to removal or cleaning, the broken up plastic material that is used in place of bioballs would be an option, flow through it would keep detritus from collecting easily, but I do not know how that would work as a pod shelter.

 

I will reread more of your posts and try to research some of your thoughts later when I can, but for now I am just along for,and enjoying the ride with you dave.

[dave w]

dave my apologies for dropping off there, health got iffy and am still getting that all back together.

 

from what you are saying I think (and that may not be worth much as the prescriptions are good) you have the right idea. i have not read anything at least that disagrees with your approach on the settlement chambers and ssuch, that being said you may wish to email one of the big aquaculture companies about their systems or thoughts, as they do massive turnovers. I know greshemH on RC is/was affiliated with one group, and rodsreef is a big name in clownfish and food (if i am not mixing up the names)

 

as far as the material to put in your "caves" and hollow areas, if they are open to removal or cleaning, the broken up plastic material that is used in place of bioballs would be an option, flow through it would keep detritus from collecting easily, but I do not know how that would work as a pod shelter.

 

I will reread more of your posts and try to research some of your thoughts later when I can, but for now I am just along for,and enjoying the ride with you dave.

 

Jager, thanks for staying with the thread while you have been ill. I sincerely hope your health issue is a temporary thing and not longer term and I hope you're better soon. If an evening in front of a fish tank with a sixpack can help, let me know again in 6 months.

 

The settlement chamber dumping to the artemia refugium is an attempt to balance the fish load of the system with more detrivores. I hope it converts the daily supply of fish poop into an equal daily supply of plankton and algae. Basically I am throwing biomass at the food/nutrient issue instead of throwing equipment at it. If the artemia biomass doesn't balance the fish poop biomass I won't hesitate to skim the artemia tank (with a fine mesh to exclude BBS). If the artemia biomass does balance the tank load, the tank theoretically doesn't need supplemental feeding.

 

Intuition (and optimism) lead me to believe that this can work but I have no clue where the system will balance. On one side of the equation is the supply of food from 2500 gallons of display plus 1100 gallons of high light refugium plus maybe 1500 gallons of brine shrimp refugium. On the other side of the equation is the supply of waste from fish and corals in the display tank. Only time will tell whether the system reaches equilibrium at 100 fish and 200 corals, or at 500 fish and 600 corals. I'm hoping for the higher figures.

 

Meantime I'm open to ideas from people like you with a lot of creativity and experience. If there are others out there with viewpoints, please don't hesitate to join the conversation. You can't get much crazier than me in using artemia to replace a protein skimmer and other filters.

 

Right now I'm excited at the possibility of generating BBS for schooling planktivores. Before I was thinking of using just the lit refugium to balance predominant herbivores (pygmy angels and tangs). Now there's the dimension that large shoals of anthias, wrasses, chromis or pyramid butterflies may be well fed.