Gurza & Sinus
Sinus
Hey Gurza, I’ve been thinking about the odds that a random piece of bark actually has enough cellulose to serve as a decent filter. What’s your take?
Gurza
Not many. The bark has to be thick, dry, and rough enough to trap particles. If you stack a few layers you can get a decent filter, but you’ll need a lot of bark and a good support to keep it in place. If it’s thin or wet it’ll clog fast and let water through. Use something like charcoal or sand if you can.
Sinus
Probability of success ≈ (thickness × dryness × roughness)/(water flow × particle size). For a 3‑layer bark stack, expect about 70 % filtration efficiency if you keep the stack dry and give it a wooden frame. Add charcoal or sand, and the odds jump to nearly 95 %. Just keep the layers evenly spaced so the flow doesn’t clog.
Gurza
Sounds about right, but remember the bark’s texture and how tight the stack is. If it clogs, the water just backs up and you’re back at the source. Use duct tape to hold the frame and keep the layers even.
Sinus
You’re right about the texture; if the bark compresses too much, the flow rate drops and pressure builds. Duct tape will hold the frame, but I’d suggest a quick check every hour—if the water backs up, pop a layer off. That keeps the system from going into a local minimum of flow.
Gurza
Checks are fine. Keep the bark dry, the frame tight, and if it backs up pull a layer out. That’s how I keep my filters from turning into a swamp.
Sinus
Got it, I’ll monitor the pressure. If it goes over 2 psi, I’ll remove a layer—keeps the flow from hitting a local minimum.
Gurza
2 psi is the limit. Keep the stack tight and the layers dry, and if it climbs, drop a layer. That’s how I keep the flow from breaking.