Help me build a closed system

[Ron]

How about filter design?    Can anyone help with that?

[scoopnet]

Try going to"Technical Resources". Scroll to the 3rd PDF file "Design of recirculating blue crab shedding sysems"> go to page 60. I used 3 rubbermaid 32 gal. "Brute" garbage cans with rubber gasket bulkhead fittings and 1-1/2" PVC pipe. It works great.  I used clam shells and dolomite gravel in the filters. You can get by with just one filter and the sump for a small tank. If you are using oyster shells, you may want to break them up a little to give more surface area for the bacteria to grow.  Put a removable screen or fiberglass filter at the end of your shedding tank return line to collect the solid waste before it gets into the filter material.  There is also a lot of info. on water chemistry at that site. I used Gluvit on my shedding tank. It works great with 2 coats,but is expensive. Buy it on line at Neals Harbor.com no tax/free shipping best price I could find.

[bigcrabrob]

i put a screen on top on my return tank so it collects all the big stuff . i use oyster shells for filter in one tank and it goes into another tank where the pump is . works great and cheap just go to a oyster house and ask them to same you the shells .

[MDblue1984]

If you use the stock tank/s you can build a table for it then use a dry sump filter for saltwater aquariums. It would work great. No worries about leak either. Easy to clean. I got a pump for ya...

I would be worried keeping them out in the sun like that.. As hot as the summers get, with black plastic, would you prematurely cook your catch?

[Ron]

The spot where I plan to put this doesn't get a lot of direct sun.   It's between the north side of my house and a fence, in a narrow area, so there is little opportunity for direct sunlight there.

[scoopnet]

MD Blue is correct about the exposed tank and the water temp.  It would be to your benefit to shade the tank with a canopy of some sort.  I bury my filters and sump about 3/4 into the ground.  This keeps the water temp. about 10 degrees cooler that the air temp.  The ability of water over 80 degrees to hold oxygen is greatly reduce which results in a higher mortality rate.  Extra aerator heads help with the oxygen during high temps.

[Ron]

The sun isn't going to be a problem.    Too many trees and a fence on one side, a house on the other, it doesn't get a lot of sustained direct sunlight.   

[flounderpounder]

Ronster, I would suggest looking at "Bio-balls".

pretty expensive vs. free oyster shell shell


I would use cycle( found in pet stores) to establish start a good bacteria colony for breakdown of nitrates and ammonia....    I can do about 10-15 in a 40 gallon rubbermaid tub with 2 airstones a foam filter and an aquarium pump..I think would def be easier with a 4x8 float more so then a " deep" container as long as temp dont get to high but I dont have room for a 4x8 float in my basement...lol

[Ron]

Got a picture of the system Jeff?

[ChrisS]

pretty expensive vs. free oyster shell shell

That depends on how well they work. There's a reason the National Aquarium uses them vs. Oyster shells.

and by free, would that mean someone will deliver a trashcan full of them to your door at absolutely no cost or are you not considering your time and fuel to go get them?

[Ron]

I have access to oyster shells.

[Mikie]

I have access to oyster shells.

I think clam shells work, also.

[Ron]

Got access to them, too.

[Mikie]

Got access to them, too.

Yeah, I figured it might be easier to come across them around the coast in NJ or DE then oyster shells.

[Ron]

There's a monstrous pile of oyster shells at the Rutgers University lab down by my bay lease.    Clam processing plant (Surfside Industries) is only a few miles up the road.   

[flounderpounder]

Got a picture of the system Jeff?

its torn down for the winter...i had some pics I posted under softshells last year. ...Ill have it up in running before to long...lol   

[Dreampixels]

Think surface area!

[jack1747]

Think surface area!

and amount of flow thru the medium.  It would have to be crushed shells to be better then bio-balls surface area. Then you would have trouble with clogging I would think.

[crab24]

plenty of surface area lava rock from home depot just rinse the rocks well before using.I also put this in the ground about 20 inches for water temps

(https://www.bluecrab.info/forum/proxy.php?request=http%3A%2F%2Fimages.imagelinky.com%2F1333450966.jpg&hash=d312acd4a3d5c770cc6956cb8f9fe8082884907d)

[Ron]

Thanks, that's a great photo.