Mr. Saltwater Tank’s 375 Gallon Reef Tank Build Show

375 gallons makes a large saltwater tank. There’s lots of swimming room for fish, lots of places to put corals and lots of opportunities for the unexpected to happen during the tank build process. Fortunately for me, I got all the issues out of the way before the tank got wet.

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Comments for this article (109)

  • Sam…not a slip. I don’t dose Alk at all.

  • Patrick says:

    Mark Thank you for the tour of your new tank!! I love what i see. i want to do my 180 Gal tank soooo bad!!! im so tired of the small tank with no sump!! i know i can do so much better with a tank that uses a sump!! I started all this with a craig’s list tank and went from not knowing a thing to pretty much a reef junkie!! if i could get a tank and filtration that will be adequate. I owe it ALL to you Mark!!when i got in to this hobby i knew i liked seeing the reef tanks and now i want the best reef tank LOL!!!
    THANK YOU!!! for everything and all your help when i bug you!!!

  • Akhil says:

    AWESOME video…loved it!!!

  • david says:

    SICK VIDEO !! this is the type of Video I LOVE !! i wish there were more awesome videos like this of big aquariums ! you did a KICK BUTT job on this Mark !! keep em coming !

  • Hai says:

    Nice i love how u got all the top notch equipments, you cant go cheap in this hobby. You get what you pay for. I guess all those books guide pay off. 🙂

  • Tim says:

    Hi Mark I’m a big fan! Where did you get the cabinet on top of the tank, it’s finominal, I want one!!!

  • Jesse says:

    Hi Mark I’m a big fan! Where did you get the cabinet on top of the tank, it’s finominal, I want one!!! LOL

  • Jesse..local woodworker made it.

  • Hai…there are many paths to the same destination and you don’t have to buy all the same gear I have. I certainly believe that you get what you pay for and keeping that in mind, you can chose less expensive gear and still have a great tank. Just keep in mind every price level has it’s pros/cons. You can’t buy a Toyota and expect it to drive like a Porsche. Both will get you to same destination.

  • Jesse says:

    Hey Mark, what is the name of the local woodworkers company?


  • Jim says:

    you think you have had issues
    do you know what
    W.A stands for ?
    Western Australia which means ( WAIT A-WHILE )
    A week means a month and a month means maybe this year
    and here’s the big one if it comes from America give them your address of the house you will be living in, in 10 years
    perfect example I ordered a tunze pump from Sydney Australia it took 3 weeks and that was after they said they lost it, and if I wanted a refund
    well I would have to WAIT A-WHILE

  • Steve says:


    Really loved the look of the custom stand that you used. I am doing an in-the-wall (well really a behind-a-false-wall that creates a service ally where everything is arranged) installation of a large tank and need to have a custom stand made to get the height that I want so the tank will present well in the den wall. I’m looking to go with a 42 inch high stand, and the 36 inch high one you got looks really solid.

    Who made it for you? Do you have contact info for them?


  • Scott says:

    Why do you not dose Alk if you also are not currently dosing Kalkwasser? How do you maintain your alk levels?

  • Que says:

    I have the exact same tank. Mine is hybrid tank by MRC (acrylic top, PVC base glass all around) and their sump..FANTASTIC! Mark..what’s the program on the 6 vortech power heads? I have 4 MP 40s now and plan to add two MP 60s, as per your recommended. Southeastern Aquariums will install a custom 30″X30″ refug. Any comments on a 75 gallon refug on a 375 DT? Are you considering a refug for your tank? Thank you

  • Eric says:

    What brand mg are you dosing? I can’t seem to find one that doesn’t require shaking before use.

  • Eric…I mix up my Mg as I buy it dry form from Bulk Reef Supply so it definitely requires mixing. Most supplements, especially magnesium will require at least some shaking as the elements can come out of solution

  • Vince says:

    Great tank. I always look forward to your videos. I assume you’ll give us a tour of fish and corals soon. I can’t believe you have that thing set up in a rental house. Dude, you gotta buy! It’s a buyers market right now and then no more moving them around when your lease expires.

  • kevin says:

    hey Mark What company made your tank? I’m in the process of working on a big tank build and want different options for tanks makers. if you could tell me that would be awesome thanks.

  • Kevin…dutch aquarium systems made the tank

  • Fred says:

    Just curious what that netgear device is attached to your aquarium controller. Very nice setup!

  • Marquette says:

    Mark, I have the same tank as a hybrid. MRC did my sump also, great product! I also have 4 of the Vortech MP 40 now and plan to add 2 MP 60s. I have the same Apex set up minus the salinity but with 2 moisture sensors for under the tank and the fish room where the skimmer send R/O unit resides. Three questions: what are your general settings for your power heads? What are your thoughts on a 70-75 gallon refugsiam for this 375 DT? Do you get any LED light creep at night from your canopy? I’m having to replace my canopy because light creeps and is annoying. Thank you.

  • Marquette says:

    The Apex system I have has 2 wife pleasures sensors one under the tank and the other in the fish room where R/O is made, the skimmer is located and the 100 gallon salt mixing unit is located. If you think your tank deliver story tried your love for the hobby we had a faulty connect on the R/O unit that dumped 45,000 gallons of water over our summer vacation last year! After six months of restoration to the basement of our home the Apex system to monitor and a number of fail safes for water in the wrong place was required. Enjoy your Friday videos and the Tuesday notes. Hope to se you in Miami!

  • Marquette..did I read that right…45,000 gallons of water? How did that happen? I mean, how long were you not at the residence for that much water to come out of a RO unit?

  • Marquette says:

    We take 10 days once a year! The connection between the water tap before the R/O unit. So we had the unbelievable combination being gone for 10 days and the break happening the second day of the trip AND it was high pressure water which cut through drywall. The only luck is that it didn’t effect anything else other than the Man Cave! Thank God my wife gave me one more chance!

  • Fred…the netgear device is a gaming adapter that lets me get my apex on my network wirelessly. Here’s the link to it

  • kevin says:

    thanks Mark but one more question how do you get in touch with dutch aquariums systems i cant find a number anywhere for them i just want a quote on a tank.

  • Jesse says:

    Hey Mark, what is the name of the local wood workers company?


  • Evan Donahue says:

    Hey Mark,

    What brand are the glass carrying suction cups (if they are yours)? I can’t seem to find a set that holds. :-/

  • Larry says:

    Hi Mark
    Great video as usual. One question why is there so much flexing on the end of you light bar?

  • Hai says:

    Mark..when you hook up your WXM module onto your Apex does it caused the apex to be very slow on the web and app browser? I got this issue.. You ever experiance this issue? I use a WD powerline wireless connection to the apex. Thanks

  • Hai…I have not experienced a slowing of the webclient when the WxM box was connected.

  • Tom says:

    When is the livestock update coming out?

  • Marquette says:

    Do you have any thoughts about the use of as refuge on your 375 tank?

  • mike gosselin says:

    I have a 220 gallon reef tank (Tank dimensions 72″ x 24″ x 30″) but I have not set it up yet I was wondering howmany and what size of the vortech mp 40 or mp 60 pumps I should get for it and were should I place them in tank.

  • billy mays says:

    Hi billy mays here!
    Mark-first thanks for taking the time to make all the insightful videos, i’m pretty new to this hobby and have gained a ton of knowledge from them.

    I was wondering where u got the bosch rails from? I was hoping to pick some up somewhere and not have to order them online, i have two ecotechs that i love but my homemade brackets in the canopy are lacking. thx again.

  • billy mays…bosch has set up regional dealers to sell their products. You can use this locator to find a dealer near you.

  • robert moshier says:

    hey mark great vid. Is your canopy topless? I couldn’t tell exactly what your radions was screwed into. Also what was sticking out the top of your canopy?

  • robert moshier says:

    hey mark great vid. Is your canopy topless? I couldn’t tell exactly what your radions was screwed into. Also what was sticking out the top of your canopy?

  • robert moshier says:

    sorry about the two comments…having issues with my laptop. One more question, why did you choose this type of connection to hook up the radions, as opposed to the kind you did on your 90?

  • Charles Boone says:


    I am in the process of looking for a 375 gallon tank, but the company I found makes it different dimensions than yours. I would prefer a 96x30x30 like yours. Could you send me some info where you bought your tank?


  • robert moshier…the canopy is topless. I designed it to have tops but decided against it as having it topless helps keep the temp in check and keeps the lights cooler.

    What you are seeing sticking out of the canopy is likely the excess mesh from the back of the tank

  • Charles Boone…I’ll send you an email to discuss

  • Stephen says:

    Who made your canopy?

  • Stephen…a local woodworker

  • Karlos says:

    Mark I’m about to purchase the BRS two part dosing system. CA and ALK. I was wondering why you don’t dose ALK but you do dose MG?

  • Matt says:

    Karlos… Mark’s tank is chewing through Mag and not through Alk … simple as that… My tank eat’s Alk and Ca and not Mag at all… I use the same salt as Mark and my friend down the road who’s dosing Ca and Mag… Every tank is simply different and can change.. like mine did… whilst I was on holiday!

    Where’s that flipping ‘going away’ pocket book guide link got to…

  • Everett de Leon says:

    Where can you get the Bosch Rexroth 20 rails? I tried googling it but couldn’t find it…

  • Everett…you have to find a dealer via this link

  • Chase says:

    I’m about to get a 33″ deep by 30″ tall. Do you like the 30″ deep and 30″ tall dimensions of the tank?

  • Matt says:

    Chase – I believe Mark was caught attempting to make reefers special lovin’ to his tank on more than one occasion … that’d probably be the best answer 😉

    The only better tank is a bigger tank… 😀

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