D.i.y. Sump And Overflow - Help Needed :)

[TaurineLittle]

Hey guys, so I'm wanting to build myself a small to medium sized sump and overflow. Now I've surfed all over the internet trying to find decent sump designs and I found they are rather hard to come by, I did find one that doesn't seem bad to me (but hey, today was the first time i actually heard of an overflow and sump filtration system... so I may have no idea what I'm talking about

). 
 
The Design Video
 
Now I thought of a couple tweaks for this design like a draw-string wash bag to hold all the bio-filter media and such but I'm curious about a few other things...
 
#1: What is the best the best order of filtration, like which media should go first, what comes next through the water flow and so on..?
 
#2: What capacity sump would be able to accommodate a tank up to 80 gallons? ( this is for a 15 gallon tank at the moment, but hopefully within roughly 6-12 months will be supporting one up to 80 gallons)
 
#3: What is a good material to make the sump box out of? (Acrylic is readily available in my area, would that be suitable?)
 
And finally #4: What are your opinions on Overflow systems? I realize they aren't the most stable ones out there but if someone has a decent or 'failsafe' design they want to share I would be greatly appreciative. I can't drill holes in the tank because it's sitting on a desk, maybe down the track once I get a larger tank I will have a proper stand for it and be free to explore different methods.
 
Thank you in advance for all the help and opinions

you guys are awesome 

 

[DrRob]

To answer your questions we'll need to know what you're planning on using the sump for. I have seen a huge variety of sumps with different designs for the simple reason that they were intended to achieve different things.
 
I have a sumped system running at the moment. It's basically there to provide a volume increase and to hide the filter and kit, however I don't need a refugium so went for large containers rather than anything more complex (it's actually a spare water butt with the top cut off and a plastic dustbin connected together with bits of spare plumbing pipes, total outlay near 0 as it was all in the shed )
 
So the answers to your questions will depend a lot on what you're trying to achieve. I can have a go at generalisations but your answer will depend after that on your tank.
 
1, mechanical, then biological, then chemical, unless you're going for a trickle tower in which case the biological needs to be in the trickle bit or there's no point.
 
2, anything so long as you remember one thing. When you turn off the pumps the flow to the tank stops but the overflow from the tank doesn't. You need a system that doesn't overflow in a power cut so you fill it with the power off, then turn the power on and you have the running volume. So the surface area of the tank and the depth of the overflow dictate the minimum sump size.
 
3, anything tank safe. clear stuff is more expensive but allows you to see what's going on.
 
4, can you drill holes in the back of the tank? that way you can have an overflow skimming of the back set at the desired water level, but do remember that single hole systems will leave you with water on the floor and an empty sump if things block.

 

[TaurineLittle]

Basically I'm wanting to use the sump for a means of biological filtration that will not take up much space in the tank like an internal would and possibly have it filtering either a large tank in future or a few smaller ones. I don't see the need for a refugium since my tank and most of my future ones will be planted tanks.
 
#1: Not 100% sure what a trickle tower is, the water will be gravity fed through the filtration media in a single water column. Hopefully my drawing skills are good enough for people to understand what im trying to do haha...
 

Drawing is not to scale.
 
#2: So basically when building the sump I need to make sure the intake into the sump has enough room to allow for the remaining water from the overflow (down to the tanks water level) to enter the sump with out overflowing?
 
#3: Alright I'll be giving all the local sheet plastic stores a call tomorrow for a quote on various sheet materials.
 
#4: It is possible to drill a hole into the back, but I am really not confident in glass work (especially drilling into it).