Questions Re: Custom 400 Gallon Tank Build

Discussion in 'Freshwater Aquarium Builds' started by Plucky, Jun 18, 2019.

  1. Plucky

    PluckyNew MemberMember

    Hello everyone, a fine day to you all! I have an interesting dilemma that I need to solve, hopefully there will be lots of strong opinions here on how to best accomplish it :)

    I am attempting to help someone who has built a custom 400 gallon tank. The canister filter or sump area where the water goes to be filtered simply *cannot* be below the water level. It just can't. Building design issues coupled with poor planning on the part of the Aquarium designer. It's set in stone. Don't bother discussing how the canister or sump needs to be below water level. I know. But it can't happen. Accept that fact, and let's move on to discuss alternatives.

    Since it is NOT possible for the canister or sump area to be below water level, I have no choice but to attempt to bring the water to a higher area (i.e. above the Fluval filters) so it can be filtered. To this end I have put together this concept (attached image) but I have a few concerns, namely -

    1) as long as the GPH of the pump is greater than the GPH of the Fluval filters, there should always be enough water for the Fluvals to work with? (assuming pump is running of course - might use toilet float valve to ensure operation)

    2) I was thinking an overflow tube to take the excess water from the sump area back to the tank, since the pump is always supposed to be moving more water than the Fluval filters, there would always be overflow extra that needs somewhere to go.

    3) how to calculate the proper size for the sump container? In theory the pump works faster than the Fluvals so I do not think it has to be very large?

    3) Any major roadblocks (from a physics / fluid dynamics perspective) that I am not considering?

    Thank you all, have a wonderful week!
    - Plucky
     

    Attached Files:

  2. ShamFish97

    ShamFish97Valued MemberMember

    Just out of curiosity, why is it that you have to do the system above water? I just got a 120g tank and have yet to purchase equipment or begin setting it up, so I'm looking to see what the technicality is behind it.
     
  3. OP
    OP
    Plucky

    PluckyNew MemberMember

    Fair question :) this custom 400 Gallon tank was constructed by someone who researched how to properly create the tank - but unfortunately they did not realize the filter issue and built the tank to completely fill the space that it is in. It cannot be raised, supported, or moved in any way. The nature of the rooms on either side of the tank prohibit placing the filters in another room. I have 2 choices - dig into the ground and create an underground compartment w/trap door to house the filter units, or find a way to house them above the tank.
     
  4. ShamFish97

    ShamFish97Valued MemberMember

    Oh wow! that sounds awesome, but also rather frustrating at the same time. Is there a way to go behind where the tank is supposed to be and create a "fish room/closet" of sorts? or are the ways the water is flowing still very important when it comes to coming from behind?
     
  5. Wraithen

    WraithenFishlore VIPMember

    Lookup above tank sumps. They kind of work like a reverse sump in that the water is pumped up into the sump, and siphoned down to the main tank. The biggest thing to get around is the weight being suspended above the main tank. After that though, it's not really anymore complicated than a normal sump, and if set up correctly, there is zero chance of a flood during a power outage.
     
  6. OP
    OP
    Plucky

    PluckyNew MemberMember

    Thank you very much for that terminology, that is the key to finding these setups. Interesting thing about these overhead sump setups is that they are combining the water tank and the filtration into one. I could potentially return the Fluval FX4s and just store the bio media in the sump tank it seems, though the Fluvals claims to have multiple stages to them so I would think that would add some benefit. Thanks again this was very helpful!
     
  7. Wraithen

    WraithenFishlore VIPMember

    Any good sump setup will have just as many stages, and much more room for your various media. You're going to need pounds of media, and a bunch of sponges or mattalomat. I wouldn't use chemical filtration unless needed, but I would probably grow something like duckweed in the sump in a way it cant get out unless the display tank was to be planted. Also, the design will be very important for this setup. Who wants an ugly setup sump with a bunch of wires and hoses coming out all willy nilly sitting over a 400 gallon custom tank?
     
  8. treadingwater

    treadingwaterValued MemberMember

    I’m curious to see if you found a solution. If not, could you build a shelf above the tank and use the sump to create a waterfall for the clean water to go back into the aquarium?
     
  9. fa4960

    fa4960Well Known MemberMember

    Why would you want both FX4's and a sump with a pump? Why not just a "reverse" sump with a strong pump in the region of 20,000+ L/H to feed the sump and then an overflow to let it run back into the tank. Just make sure you have excess overflow to prevent a flooded sump, instead of a flooded tank which is my concern with a normal sump.

    Alternatively you could look into pond filtration. They typically always have the filter above water level and use drum size canisters fed by a pump and then overflow back into the pond.
     
  10. OP
    OP
    Plucky

    PluckyNew MemberMember

    Thank you all for your input.

    ShamFish97, yes I pushed the water closet idea hard, but it was abandoned due to space & noise issues. Owner insists that over the tank is the only possible space available for filtration equipment.

    I have decided after reviewing everyone's comments and the many DIY videos on overhead sumps, to ditch the Fluvals and just add the mechanical and bio filtration materials to the sump itself. I will post photos once it's done.

    I will attempt to use 2 Aquaneat 800GPH power heads to pump the water into the sump (to achieve something close to 1600GPH turnover, since the tank is 400 gallons). I don't expect them to perform at 800GPH but if I can get even 1200GPH I think that would be pretty good. Input tubing is 5/8in. I plan on using 2 to 3 output bulkheads at 1in diameter to ensure adequate outflow. Coarse & Fine mechanical filtration, followed by Ceramic noodles & Bio Balls. The actual sump container (in this case, a window planter) is about 4 gallons of volume and I need to push ~27 gallons per minute through it, so this should be lots of fun lol. Hopefully the output holes won't be shooting water like a fire hose. Updates to follow!
     
  11. Wraithen

    WraithenFishlore VIPMember

    I hate to say it but unless you worded something wrong, this flat out will not work. 4 gallons of volume isn't enough to house the media you would need. You need at least 1 gallon of just bio media. That would give you about 3 gallons water in that planter. And that doesn't incorporate mechanical filtration. By the time you add baffles and sponges, you're looking at no water in there.

    I would also not use powerheads. I would pull into the sump with a pond pump instead of trying to push up with powerheads. This requires 0 pressure in the system compared to using powerheads. What if a line pops off? I'd rather buy a new pump every month than fix a 100 gallon spill a single time.
     
  12. fa4960

    fa4960Well Known MemberMember

    Can only agree with @Wraithen here. I am running a 250 liter / 65 Gal sump on my 1250 L / 330 Gal tank and although there is no doubt I could run with less there's is no way you will get enough biological filtration with 4 Gal volume, unless of course the setup is a planted tank with now more than a 100 small tetras. I am afraid you will need to go back to the drawing board and find a way to get yourself at least 25 Gal and ideally much more - depending on future stocking.
     
  13. OP
    OP
    Plucky

    PluckyNew MemberMember

    Thanks for the input! I will look into a much larger volume for the sump container. I am curious to know why you believe using a pond pump would create 0 pressure in the system? Either way the water has to be pushed up the same vertical distance to the sump container, seems like any pump or power head would need to use pressure to accomplish that? Thanks again!
     
  14. OP
    OP
    Plucky

    PluckyNew MemberMember

    Thanks very much. What materials did you use to build the walls of your 65 gallon sump?
     
  15. OP
    OP
    Plucky

    PluckyNew MemberMember

    Currently looking at Trigger's Ruby sumps (30 or 36 model) as possible replacement based on your suggestions. Acrylic seems to be the only option for the amount of volume I will need. Now to see if I can support 300 lbs above the tank....
     
  16. fa4960

    fa4960Well Known MemberMember

    My sump is basically a fish tank turned sump, which is the case for most I believe. There are plenty of videos on youtube for a DIY sump. In your case I would agree that acrylic would probably be best in order to save some weight where possible.

    A completely different solution would be to abandon the separate sump and build it into the tank instead. You will of course lose some of the 400 Gal but maybe it would look and work better overall?



    I have a 40 Gal with this kind of setup and except for losing some tank volume it has some great benefits:

    - No need to find place for a sump or a canister
    - You can decide the size yourself, i.e. 100% customizable to your needs
    - You can use a smaller pump compared to a sump as it is not lifting water - just pumping it back into the tank at the same level
    - No risk of any kind of flooding. Mine has both a surface overflow and an inlet close to the bottom so impossible for everything to get blocked in a short time frame

    Only real downside is the loss of tank capacity and maybe some aesthetics but I cover mine withe the black wrap I use for background. Here is a picture of the end of my tank
    20190701_120937.jpg
     
    Last edited: Jul 1, 2019
  17. bentaz

    bentazNew MemberMember

    The above option would be perfect I think too.
    No extra weight to manage, zero lift for your pump so you can get the full flow rate.
     
  18. Wraithen

    WraithenFishlore VIPMember

    Didn't even think about an in tank sump idea. I agree, it's perfect for the client. Just plan it well so maintenance doesn't include having to be suspended from the ceiling!
     
  19. bentaz

    bentazNew MemberMember

    Maybe stick it in one end where it's easier to access.