DIY Help/Advice on a New (to me) 120 Gallon Tank

Discussion in 'DIY' started by jctse, Sep 4, 2014.

  1. jctse

    jctse Guest

    Need some assistance on a 4x2x2 fixerup tank. It's missing the overflow in the back right corner so I just have 2 holes in the bottom back right (1-1/2 and 1-3/4). The overflow on the back left is still there but the 1-1/2 and 1-3/4 are just holes and there's no bulkheads. I have an extra 29 Gallon Tank that I would like to use as the sump. I currently have a kessil a350w and plan to get one more for this. Planning on Mixed reef and not really big on fish... more on coral. Been doing 2 nano reef's for about 3 years but never even had a sump.

    Initial questions are do I need both overflows or just plug up the right two holes? If its better to have can I just have TAP (or the like) just cut some pieces in and create one. Is that size sump adequate?

    Big Thanks for any suggestions you can offer.
    Last edited: Sep 4, 2014
    swayd likes this.
  2. dswong01

    dswong01 Supporting Member

    please post some pictures
  3. HiFidelity

    HiFidelity Guest

    29 may be a little small, for a 120 I'd run a 40 or 50 gal sump but a 29 would work for a little while if you don't have anything else...

    I'm guessing the tank has 2 corner overflows? if so and you're asking if you can just plug up one side, yes of course you can do that but you can also get some new bulkheads & some acrylic, it's pretty easy to build your own overflow specially if you get your acrylic pre-cut. You have options at least...
  4. swayd

    swayd Guest

    You can plug them, use them as return if you would like, or just get a new piece of acrylic and to make it an overflow again. Yeah I would throw at least a 40B under that bad boy.
  5. denzil

    denzil Webmaster

    Personally, if it were me, I'd just plug up all the holes and go with a ghost overflow. Also, a 29 gallon won't be enough, especially to cover the volume of water that gets displaced from the tank and into the sump when the return pump is turned off.
  6. aqua-nut

    aqua-nut Supporting Member

    I have a 120 and went with a 40B sump. Cheap and has enough capacity for drain down. Very important!

    You could use the two holes as a closed loop, plug or get an OF.

    Is this a glass tank? How are the seals?

    With two holes in the one OF you could do a Herbie drain. One OF doesn't have as much area as two so total flow will be less and there should be less efficient surface skimming.
  7. rygh

    rygh Supporting Member

    +1 on drain capacity concerns. At least a 40G sump is needed.
    Personally, I would go as big as possible in the space you have.
    You may change skimmers, add cheato, socks, who knows.
    Get a cheap used tank.

    I would really suggest building a new overflow, and not plugging the holes.
    It was designed for two, probably for a reason.
    Doubling the flow through an overflow could add a lot of noise.
    Water over the top + through pipes.
    And depending on size of those holes, might even have issues handling the flow.
  8. gaberosenfield

    gaberosenfield Juvenile Chromis over an Acro in the Red Sea

    IMO you might as well fix it up so you have two herbie style overflows. It gives you more options. You should go for as big a sump as feasible. If you have an external pump and skimmer you could probably get away with a 29. But if you have internal pumps and skimmers you need a 40. If you want a fuge section in your sump you need even more space. Just my opinion of course. It is always easier to have more space.
  9. jctse

    jctse Guest

    So I'm going to pick up a 40B during Petco's next sale (December?). Picking up another Kessil A350W (for a total of 2) this weekend. Going to fix the Overflow with some plastic from Tap.

    I have two holes for each overflow (1 1/2 and 1 3/4). When I look for the bulkhead options from BRS they have a bunch of choices for threading. What should each be used for since they are different sizes for a reason? Should both bulkheads be threaded or just the return one since that one has some pressure?

    Is an Eheim 1262 about right?

    Will I just have one 250 watt heater or is there a benefit to having two smaller ones?

    Attached Files:

  10. gaberosenfield

    gaberosenfield Juvenile Chromis over an Acro in the Red Sea

    If I were you, I'd use all the holes as drains so you can implement a Herbie style drain on each side. Smaller holes are the full siphons and larger holes are the "emergency" drains. Just run a return over the top or drill a new small hole on the back of the tank for a return.

    I prefer all threaded bulkheads because they allow you to easily and securely affix pipes and fittings and allow you to remove them relatively easily if you want to later.

    I don't know about Eheim stuff so someone else will have to chime in. But if that is a return pump you're talking about, you want between 3 and 10 times total system turnover per hour. With a 120 gallon DT and 40 gallon sump, that's (160 x 3) 480 to (160 x 10) 1600 gallons per hour after head loss on the return pump. Don't rely on your return pump for DT flow; get wavemakers and/or a wavebox for that.

    Two slightly undersized heaters is safer so that if one fails in the on position your tank won't cook, and if one fails in the off position your tank won't freeze.
  11. yellojello

    yellojello Supporting Member

    I have the exact same setup as you. Got a used 4x2x2 with the right side overflow removed. The guy used that side with a drain valve and hose for water changes. The 4th hole I capped off. You can see my setup in my link in my signature.

    Overall, I really wish I made it back to an overflow. First, the small excess space between bulkhead and drain tube collects detritus and smells bad when I drain it, thus causing some water quality issues. Although, it is convenient to drain from there. I feel like using a siphon tube to drain is much better when you can suck up the rock funk and sand.

    Also, the extra water going into your sump will make filtration and water exchange much better. I feel like I'm not getting enough.

    Third, if one overflow fails, or junk and algae block the overflow walls, there is no backup. Ive had it happen once where a turbo snail got into the drain. Although I corrected the problem and it never happened again, you never know. (The standpipe drain was missing the screen cover, but I was able to find a replacement after)
  12. yellojello

    yellojello Supporting Member

    I'm not sure which brand tank you have, mine has a curved overflow wall, but should be the same parts I believe. This is what you may need if you want oem.

    If I recall, I called tech support and said my overflow drain pipe strainer was missing, and instead of just sending the strainer for free, they sent me the whole megaflow kit as linked above for free. I think they don't have just the strainer screen as a separate piece, that's why they sent the whole kit. You may try calling them and score a free one too.
  13. Coral reefer

    Coral reefer President

    Smaller holes are meant to be returns. Larger holes are meant to be the drains. If you want there to be less water noise you could do as said above with the her is style, but I don't thin its necessary, especially if you want to keep it simple.
    Eheim 1262 will be great!
    I think the bulkheads you will want are 1" for the drain and 3/4" for the return. I know this isn't the actual size if the hole in your tank but it is the size if the. Ill head you want to buy.
    The pieces I would use would either be threaded w Teflon tape, or slip fit w PVC glue. It depends on how much space you have and what you are trying to do. I often like to use flexible PVC for drains and sometimes even vinyl tubing for returns. Rigid PVC works well and is strong, and if you use unions you can take it apart and reassemble it if and when you need to.
    One thing I definitely recommend is to run a media reactor off of the return pump. It doesn't take away very much flow and you don't have to run an additional pump.
  14. I'd never waste a hole in the tank for draining. Whenever I plumb a tank, I always add a "t" into the overflow line. I connect a nylon hose with a valve to the "t". I cut a piece of pvc that's just taller than my buckets and I slip it into the valve without gluing it. This serves as my water change access point. The pipe keeps the valve up out of the water so everything stays clean and dry. When I'm done, I disconnect the pipe and tuck the valve/hose behind the tank and water changes are a breeze! One note, you should install the hose on the 90° leg of the "t" so that your main overflow passes straight through so you don't lose flow to your sump.

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