Sump Design Thoughts

Discussion in 'DIY' started by gunit, May 1, 2014.

  1. gunit

    gunit Guest

    So I'm getting closer to starting my 50g build and am in the process of planning out (and hopefully building my sump).

    So my cabinet which I'll be putting this in is 26"x15"x30" so I'm currently planning on building my sump with a 20g (24"x12"x16") tank. My plan to to use the extra space in the cabinet for my ATO reservoir and any dosing containers. I'm not sure how exactly I'll mount this stuff, but for now I want to try to nail down my sump design.

    Here is what I was thinking so far:

    Basically I'd be running a Herbie drain from the display tank and have it feeding the skimmer chamber. I'd then split off the return so that I could have 100% control over how much flow my refugium gets. I'm not worried too much about the fuge water being post-skim since I don't plan on running a skimmer that will have a higher skim rate than my return pump is running at.

    Anyway thoughts on this plan?
  2. kavcheung

    kavcheung Guest

    Wow, what great timing! I just drew up a really ugly sketch for a sump myself. From what noticed with my sump is that the skimmer will not pick everything so you should maybe add some sponges in those little spaces between the return chamber and skimmer, otherwise poop will go back into the main tank and fuge? Wouldn't it be better if the fuge was in the middle? It will act as more filtration before returning to the main return pump. Having the return pump split into the fuge like that, wouldn't it eventually overflow? Water is getting constantly pumped into the fuge and the water has no where else to go.

    I could be totally wrong, so hopefully someone else can chime in. So I can learn something too.
  3. rygh

    rygh Supporting Member

    Sponges are nitrate factories unless you clean them almost daily.

    That looks like a pretty small return pump section.
    Can it handle the back-flow if your return pump stops?
    If not, it will overflow into the skimmer area, and when that happends, your skimmer
    overflows, and all the gunk pours back into the tank.

    The three baffles on the skimmer-return is a bit counter-productive.
    That left baffle will create a waterfall, which adds bubbles. (Assuming fairly high flow)
    Better to do 2 or 4, not 3.
  4. bluprntguy

    bluprntguy Webmaster

    Especially with a refugium light in the sump, your baffles may become a maintenance item that needs regular cleaning. Less is more IMO.

    Splitting the return seems like a good idea, but it becomes a balancing act of how much water goes back to the tank and how much gets diverted to the refugium. Unless you do an adjustable DC pump, then adding more flow to the refugium always results in less flow to the display tank.

    I think you'd want the overflow from the tank during "power off" to infiltrate the refugium section before it begins to raise the water level in the skimmer section. You can set the skimmer on some blocks and lower the refugium baffle to make that happen.

    No plans for a media reactor?
  5. gunit

    gunit Guest

    I'd rather have some stuff get recirculated back to the tank (and then hopefully back to sump/skimmer) instead of having to worry about cleaning sponges/etc to avoid nitrate/detrius traps.

    kavcheung, the sump shouldn't overflow with the returned T-ed off like that since it is part of the return pump loop. Basically the return pump will actually be pumping the main tanks return rate and then amount that is flowing into the refugium and is being fed water at each of those rates from each chamber. Or in real numbers, I plan to have a main tank turnover of around 250gph and a refugium flow of 50gph. So my pump will be pulling water at 300gph, but will be getting 250gph from the skimmer chamber and 50gph from the refugium overflow.

    Mark, generally how big do you try to have the return section? I'm hoping to have at least a couple gallons worth of space in the return section for backflow from when the return isn't running. I figure that for my overflow I'd have roughly 1.5 gallons which would drain down (12" long overflow that is roughly 5" deep and the herbie drain would be ~6" below the surface) so call it 2 gallons total of back-flow.
  6. rygh

    rygh Supporting Member

    You mention one part for return section, for the overflow, yes.
    Another key is how far down the main tank water drops, from the siphon on
    your returns, before the siphon breaks.
    Basically, how far below water level are your return nozzles.
    In your case, even if only 1 inch, that is another 3.3 gallons.
  7. gunit

    gunit Guest

    Hmm yeah forgot about the backflow... I'll have a siphon break and will be using something like this for my return jet. If my siphon break is on part of the tubing that is in my overflow will I still get the full amount my return head is under water siphoned off when the return stops or could it stop once the siphon break holes were out of the water?

    As for the sump, would something like this be better? I think this should give the return close to 7 gallons capacity before it'd flow into the skimmer section which seems about right since it'll have roughly 4" (or roughly 2 gallons) of water in that section while the pump is running.

    Screen Shot 2014-05-01 at 6.25.07 PM.png
    Philip, yeah no planned media reactors for now. I'm trying to keep the refugium as big as possible since I hope to have that be filled with as much macro algae for nutrient export. But if my return section isn't big enough then I'll definitely lower my refugium baffle so as not to have a mess every time I turn off the return pump.
  8. bluprntguy

    bluprntguy Webmaster

    Assuming you are going to add an ATO, I'd suggest the return pump chamber should be just big enough to fit the pump comfortably. Since this is the only place there should be fluctuating water levels during normal operation, the smaller chamber means less water evaporates before the ATO kicks on. The larger return pump chamber in this new option means more water has to evaporate before your ATO would be triggered which may cause greater salinity fluctuations than the first version.

    Also, the general rule of thumb for macro algae refugiums for nutrient export is at least 25% of your display tank volume. In order to be effective, I think you'd have to devote at least half of your sump to macroalgae. I know kgoldy isn't on Nano Reef anymore, but you may want to read through his build history. He had a 90 display and 40 refugium and then added a big HOB refugium to that. He's the only person I've seen that's really had an extremely successful set-up that used a refugium for all the nutrient export.
  9. aqua-nut

    aqua-nut Supporting Member

    Siphon breaks are great but not foolproof.

    With that configuration in the OF, part of the return water will never make it to the tank. Also it might be hard to maintain the siphon break hidden within the OF. Once the holes are clogged there will be no siphon break. It's best to design enough sump capacity to handle drain down to the return opening.
  10. gunit

    gunit Guest

    I thought that between my skimmer and refugium I would have sufficient nutrient export. Is that not right? Will I likely end up needing to run a media reactor to help?
  11. rygh

    rygh Supporting Member

    +1 on not using holes for siphon breaks.

    Too small, and they clog. Too large, and what is the point.

    If above the water line, they are noisy. Especially if you put them on that side, since
    the pressure will be a bit higher also.
  12. rygh

    rygh Supporting Member

    Depends on your bio-load, and how aggressive you are in the refugium.

    It is quite possible you will run GFO for phosphate, and Carbon to keep the water from yellowing.
    But that you can put them in media bags and simply float them in the sump as well.
    So media reactors are far from required, but would not hurt to think about.
    A good idea would be to put them on the return->fuge line.
  13. bluprntguy

    bluprntguy Webmaster

    The theory on using macroalgae for nutrient export is that you need to harvest and remove enough algae from your system on a weekly basis to "remove" the nutrients that you are adding (primarily by feeding). You can theoretically figure out what you need by doing the math. But other people have done it already, which leads to the general consensus of 25% of the display volume needing to be devoted to macroalgae growth in order for it to be effective.

    You can try to rely on things like GFO, purigen, and carbon to help make up the difference if your refugium is undersized. In my experience, it's hard to find the right balance between enough GFO to pick up the excess and so much GFO that it slows or stops your macroalgae growth the entirely. The center section of my sump was originally intended for macros, but it wasn't large enough to do the job, so I removed them entirely.

    Since you are building your sump from scratch you may want to look into algae scrubbers instead. They take up less space and may simplify your sump design. If you can grow hair algae, you can use an algae scrubber. It doesn't get much simpler than that.
  14. Coral reefer

    Coral reefer President

    Algae scrubber comment? And not from Marc? Weird
    I agree u need a lot of space for macro to do all the work. I think more like equal to or larger than display volume tho. Obviously depends on bioload and feeding etc...
    Agree hard to balance gfo vs macro and keep growth good. That and the volume needed are why I usually go with gfo instead of refugium.
    While a reactor isn't necessary for gfo use, it is MUCH more efficient IMO, I almost always go with a reactor when using gfo. Carbon I do just put in media bags often tho.
  15. gunit

    gunit Guest

    You guys have me paranoid now about my plan for just using my skimmer with macro algae growth supplementation for nutrient removal :)

    After looking into algae scrubbers though I'm intrigued. I'm thinking about building a UAS (upflow algae scrubber) chamber into my sump and decreasing my refugium size to make room. Then my refugium will just be a deep sand bed isolation tank where I can keep frags a bits of live rock.

    Has anyone here tried designing a UAS chamber for their sump? Any tips?
  16. rygh

    rygh Supporting Member

    The UAS designs out there seem to be a bit hit/miss. Quite a few people have switched back to
    normal waterfall type. But some have had good success.
    I currently run a waterfall scrubber in my sump.


    A simple way to look at it is Water Changes required = Bio-Load - Equipment
    You always need some water changes. How much depends on how large of a bio load, minus
    the equipment used to reduce nutrients. So it is not a pass/fail sort of equation.

    So: I can confidently say that your original plan, with enough water changes, would be just fine.

    But then you need to decide, what is the biggest pain in the rear?
    Endless water changes? Vodka? Scrubber? Etc?
    All a tradeoff, and WAY different from person to person.
    And something you do not have to decide up front.

    BTW: If you add a good algae scrubber, all your macros will die.
  17. gunit

    gunit Guest

    So with an algae scrubber, would the recommended 10% water change schedule go from every week to every 2? Every month?

    Just trying to get the sense of rough pros and cons since I'm coming from dealing with a nano where I do 10% weekly since I don't dose and need to keep my Alk and Ca up (in addition to nutrient export).
  18. Vincerama2

    Vincerama2 Evil Overlord

    My thoughts, without reading other comments to give you an undiluted view;

    1) Skimmer section baffle is not tall enough, it is shorter than you refugium baffle. The skimmer baffle needs to be the tallest one because they only thing that requires a CONSTANT water level is your skimmer. I believe you don't need the triple baffles, they only take up precious sump space. Make sure your skimmer fits in there if it is an in sump skimmer.

    2) Refugium ... interesting T-off, but why the high baffle (see point (1) above)... I assume it's to get as much volume as possible. I'd drop the fuge baffle to about a half inch shorter than the skimmer baffle and I'd move it so that the skimmer section simply overflows into the fuge section.

    3) return - I would give the return section the largest portion, because evaporation will show itself only in this section. Whatever the lowest section is is where you'll see it. If it evaps too much (ie; your ATO can't keep up or runs dry by accident) then your return pump will be pumping air.

    4) Plumbing, forget the complicated T-plumbing IMHO, let the return pump use all of it's pumping power to overcome the head pressure and give your tank extra flow.

    So in a nutshell, I would do ... well, I would do what I did... drain/skimmer area ... just barely large enough... one single baffle. This flows into the fuge section, if you have one, this has a slightly shorter baffle which has teeth in it to prevent algae and stuff from flowing into the return section. Return section has a good wide area so evaporation does not cause drastic water levels, causing your ATO to run constantly or in frequent bursts.

    My current ghetto design (temporary) is simply a 30g tank, with a storage box in it that acts as the skimmer/drain section, then the return pump sits in the tank next to the storage box. This is because my current sump is under another full tank that can't be moved. However I will build a new one and sell that sump with that aquarium.

    My new sump will have two section. Skimmer and return, if I want to fuge it up, I'm just going to put an egg crate divider in there and a lump of macro algae and some rock maybe. I want this section to have lots of volume.

    My 2 cents. on your first diagram. I've not read through all the replies including your newer design. Just wanted to give some raw knee-kerl reaction without bias.

  19. rygh

    rygh Supporting Member

    Not really that simple.
    With a scrubber, you can completely stop doing any water changes to reduce nitrates.
    But unfortunately there are many other reasons to do water changes.
    And those reasons will change depending on how you dose, what you dose, and specifics of bio-load.

    Personal opinion: It seems that 10% per month (not week) works well for me.
    But it is very common to be < 5% due to laziness.
    When I do more, I do not notice an improvement.

    BUT! That laziness is a bit dangerous, if you forget to test. My Alk drifted way high recently,
    and my tank is still a mess recovering.
  20. Vincerama2

    Vincerama2 Evil Overlord

    I highly suggest going very simple at first. Add that algae scrubber stuff later if you want to.

    Run a nice skimmer and do your water changes and you should be good.

    Although sub-optimal, my 58G runs quite well for the anemones (including aiptasia) that live in it and it's been a few months since the last water change (that will end tonight, it's about time to give it an almost 10% change).


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