Ultimate sump design for planted freshwater aquariums.

I'd like to come up with an 'ultimate sump design' for freshwater planted aquariums that incorporates minimal CO2 degassing, excellent mechanical and biological filtration, the best possible oxygenation without degassing CO2, easy access for cleaning/ replacing mechanical filters and siphoning the sump bottom if necessary AND finally, pleasing aesthetics.

Tom, I know you use the trusty old duct tape around your sump inlets to minimise CO2 degassing, but I can't help but think this is messy and unprofessional (no offense meant there), and that the right design can eliminate the need for this. I would like to learn from your extensive knowledge and experience to come up with something neater and more efficient.

I'll see if I can get a drawing of ideas I have up in the next week or so.

Also, I have one other question: Is the 'bean animal' overflow better (in terms of minimising degassing) than a 'durso' style overflow feed to the sump?

Cheers,

Neville.

 

Here's a pic of what I'm envisaging so far. The glass slots to hold fine filters on the design below - I envisage some kind of foldable plastic frame (similar to what you find in some hang on filters) that a sheet of dacron can be sandwiched in and then closed, and slid into the glass slots to provide a fine filter.



Re overflow feeding to the sump, I'd like something that is hard plumbed into the tank. I don't particularly like the look of hang on overflow boxes. I looked up herbie overflow, which it appears can be hard plumbed. My question is: Why is less air sucked into an open topped pipe (so I imagine the water would to some extent 'vortex' down it, a bit like a bath plug hole) than a durso style?

 

Did you look over the drawing above, Tom? Aside from not using filter socks, & therefore not needing a latched, sealed section AND not having an overfill safety overflow, I think it covers most of what you've laid out. I think the mech filtration I've incorporated into the design will be easier access than a sock inside latched/ sealed section (as well as being easier to build), and pretty much as effective. So I just need to add a safety overflow pipe.

What do you think?

 

I've got two sections for fine filtration. One before the biological section and one following it. Sponges are primarily there to prevent bubbles flowing through to the next sections, and to act as coarse pre-filters for larger sediment.

In terms of clogging... so long as the top of the fine filter slide-in apparatus is an inch or so below the top of the sump, water can flow over it if it is clogged... so that's a good enough bypass. If it does clog to that level within a fortnight (which I doubt it would), then I could add a design with an overlow pipe leading to the low side of the sump (under water level) to prevent any turbulence/ de-gassing of CO2 from water flowing over top of the fine filter slide-in apperatus. Personally I service these types of filters once fortnightly for customers, and once weekly to once fortnightly for myself. I remove the dacron pad (when I say dacron, that's the polyfibre sheet wadding used in upholstery - I don't know how many micron it is, but it's pretty fine) and throw it away. That's why I prefer it to bag filters... cheaper (can be bought in large sheets and cut to size), still fine enough (IMO) and easier to access than a bag in a sealed section.

 

I also have a question about sealing the bio section of the filter.

I know that you (Tom) say that sumps always give you higher O2 levels than other filtration types. However, I can't see any reason for this occurring in the bio section if it's completely sealed, as even though the water may be highly broken up/ agitated within that section, if no other O2 is in that section aside from what the water is already carrying, then O2 levels cannot be increased through this agitation.

My theory is that the greater O2 saturation has to come from the water flowing down the overflow system, and possibly having some minimal turbulence as it flows over sump dividers... which is still more surface agitation than you will get from most canister returns.

At the end of the day, O2 levels increasing in water MUST mean some CO2 degassing, unless you actually add O2 into the bio section of the filter similar to how you are adding CO2 to use it as a reactor as well... which I've never tried, but I wonder if it would work (bubbling pure O2 into a reactor section of a filter)?

 

I realize that the two gases are independent of each other... However aside from adding them to the water via an interventionary method that doesn't break surface tension in the open atmosphere (ie a sealed reactor), or via plants 'pearling', the method of O2 addition means that CO2 is degassed - which you acknowledged above in your statement relating to overflows & weirs.

Does this imply that it's not the sump that increases O2 levels, but the method by which water gets to it?