Post by sdboers on Mar 18, 2015 7:41:25 GMT -5
G'day,
I mentioned in one of my previous threads that I wanted to try a DIY fluidized sand bed filter as one of my next projects. I probably won't get to the actual project for a month or more - but there are lots of choices to make before I actually start building. I wanted to kick this thread off to have that discussion, bounce ideas, and talk about some of the design considerations before I end up too far down any particular path. I have no idea if this project is going to work out well, or end in dismal failure, but I fully intend to enjoy the process either way. I will spew out my thoughts, but am more than open to alternate approaches.
Material: I want the FSB to be clear for several reasons. I want to be able to monitor the fluidization, plus - I just think they are really cool to watch... Acrylic and clear PVC are just too expensive to use, although pretty easy to work with. I'm likely going to go with a clear glass cylinder vase as the main body of the filter. These are readily available and fairly inexpensive at craft stores, on ebay, walmart, etc. Looking at the dimensions of the TMC, it would appear that a 4" OD vase would be sufficient. Here is an example of what I'm thinking: www.michaels.com/ashland-cylinder-glass-vase-18in/10186782.html#q=cylinder+vase&start=10 . At 18" tall, this would be right between the size of the TMC 1000 and the TMC 1500. 18" tall would allow me to place it either inside my tank, or outside, depending on the rest of the design. Anyone else have ideas on material that would work better?
Internal or External: An internal FSB would be the easiest to create as I wouldn't have to worry about making the vessel water tight under pressure. If it is below the surface, a simple mesh cover would allow water to exit the top and into the tank. If it is above the surface, water can simply exit and flow over the sides and back into the tank. External is a lot more flexible in terms of placement and configuration, but has the challenge of being able to properly seal it. Thoughts?
External: Since there are more problems to solve with external - let's assume external for a moment and I'll scribble down my ideas. My idea is to take a piece of 1/2" acrylic (or substitute) and cut a circle equal to the outside dimensions of the glass vase. Then using my router table, cut a 1/4" groove around the edge, reducing one side to the inside diameter of the vase. Lots of places to buy o-rings, so the next step would be fitting a o-ring on that lid that fits snug. The idea would be to sandwich the o-ring between the lid and the top of the vase. To that end I would need two draw latches like the following: www.leevalley.com/en/hardware/page.aspx?p=48576&cat=3,41399,41433 . The hook part would be screwed into the lid, the latch part would be affixed to the side of the canister using something like gorilla glue epoxy: www.gorillatough.com/gorilla-epoxy . With the lid being acrylic, it could easily be drilled for inflow and outflow fittings. In fact - with my tap and die set - I could even thread it for screw in fittings.
Inflow: This is the area where I am most vague, so please comment away... The inflow fitting would be drilled dead center on the lid. I'm thinking a 3/4" PVC rigid pipe would be good to get the water flow to the bottom of the vessel. My current thoughts are to leave this about 1/4" off the bottom of the vessel, and cut 1/8" wide slits about 1/2" up the pipe all the way around. The bulk of the water would shoot straight down, diffusing as it hits the bottom of the glass. Excess water would be able to exit via the side slits. I think Devon mentioned using marbles as a diffuser - I like that idea. Would the water flow be enough to cause the marbles to rattle around though? I would also add a check valve to the inflow to avoid the sand backing up the inflow tube that was described.
Media: Marbles for the diffusing, pool filter sand (or possibly aragonite sand) for the sand bed. How much sand? Off the top of my head I'm thinking between 1/4 and 1/3 of the volume of the cylinder?
Outflow: Outflow would be simply through the second hole (or holes) drilled in the lid and be hooked up to a return spray bar in the tank.
Pump: Jury is out on which pump (thinking Lifegard 4000), but the pump would be fitted with a pre-filter - likely of my own construction as well. Haven't thought that far ahead yet.
Thoughts???
Sean.
I mentioned in one of my previous threads that I wanted to try a DIY fluidized sand bed filter as one of my next projects. I probably won't get to the actual project for a month or more - but there are lots of choices to make before I actually start building. I wanted to kick this thread off to have that discussion, bounce ideas, and talk about some of the design considerations before I end up too far down any particular path. I have no idea if this project is going to work out well, or end in dismal failure, but I fully intend to enjoy the process either way. I will spew out my thoughts, but am more than open to alternate approaches.
Material: I want the FSB to be clear for several reasons. I want to be able to monitor the fluidization, plus - I just think they are really cool to watch... Acrylic and clear PVC are just too expensive to use, although pretty easy to work with. I'm likely going to go with a clear glass cylinder vase as the main body of the filter. These are readily available and fairly inexpensive at craft stores, on ebay, walmart, etc. Looking at the dimensions of the TMC, it would appear that a 4" OD vase would be sufficient. Here is an example of what I'm thinking: www.michaels.com/ashland-cylinder-glass-vase-18in/10186782.html#q=cylinder+vase&start=10 . At 18" tall, this would be right between the size of the TMC 1000 and the TMC 1500. 18" tall would allow me to place it either inside my tank, or outside, depending on the rest of the design. Anyone else have ideas on material that would work better?
Internal or External: An internal FSB would be the easiest to create as I wouldn't have to worry about making the vessel water tight under pressure. If it is below the surface, a simple mesh cover would allow water to exit the top and into the tank. If it is above the surface, water can simply exit and flow over the sides and back into the tank. External is a lot more flexible in terms of placement and configuration, but has the challenge of being able to properly seal it. Thoughts?
External: Since there are more problems to solve with external - let's assume external for a moment and I'll scribble down my ideas. My idea is to take a piece of 1/2" acrylic (or substitute) and cut a circle equal to the outside dimensions of the glass vase. Then using my router table, cut a 1/4" groove around the edge, reducing one side to the inside diameter of the vase. Lots of places to buy o-rings, so the next step would be fitting a o-ring on that lid that fits snug. The idea would be to sandwich the o-ring between the lid and the top of the vase. To that end I would need two draw latches like the following: www.leevalley.com/en/hardware/page.aspx?p=48576&cat=3,41399,41433 . The hook part would be screwed into the lid, the latch part would be affixed to the side of the canister using something like gorilla glue epoxy: www.gorillatough.com/gorilla-epoxy . With the lid being acrylic, it could easily be drilled for inflow and outflow fittings. In fact - with my tap and die set - I could even thread it for screw in fittings.
Inflow: This is the area where I am most vague, so please comment away... The inflow fitting would be drilled dead center on the lid. I'm thinking a 3/4" PVC rigid pipe would be good to get the water flow to the bottom of the vessel. My current thoughts are to leave this about 1/4" off the bottom of the vessel, and cut 1/8" wide slits about 1/2" up the pipe all the way around. The bulk of the water would shoot straight down, diffusing as it hits the bottom of the glass. Excess water would be able to exit via the side slits. I think Devon mentioned using marbles as a diffuser - I like that idea. Would the water flow be enough to cause the marbles to rattle around though? I would also add a check valve to the inflow to avoid the sand backing up the inflow tube that was described.
Media: Marbles for the diffusing, pool filter sand (or possibly aragonite sand) for the sand bed. How much sand? Off the top of my head I'm thinking between 1/4 and 1/3 of the volume of the cylinder?
Outflow: Outflow would be simply through the second hole (or holes) drilled in the lid and be hooked up to a return spray bar in the tank.
Pump: Jury is out on which pump (thinking Lifegard 4000), but the pump would be fitted with a pre-filter - likely of my own construction as well. Haven't thought that far ahead yet.
Thoughts???
Sean.