MMcDonald 285 gallon Plywood Build Thread

subscribed! i concur with others on going with a RDSB instead of putting that much sand in the display itself. if you ever have a problem with a RDSB you can easily take it offline and work with it, however if you have a problem with the DSB in the display you'll be pulling out all the rock and trashing the tank anyways to get to it and maintain it. plus at the overall depth you're talking about (30") its already going to be a fragile matter of simply moving/placing corals.

With how much liverock you'll have in the display you'll have plenty of room for de-nitrification with say a 2" sand bed IMO.

 

I know several folks with 24" tall tanks lit solely by t5ho. They don't have issues with PAR even at the bottom.

If it is taller than 30" that would probably make me feel MH are necessary.

 

sorry,
I didn't mean to hijack your poll with the DSB question.
I voted 27" to 29" depth because if its any deeper than that it better be big enough for me to scuba in for maintenance

 

Okay.... to keep you updated...

Current concept,

• 26" water to sand depth
• 2" additional sand bed in DT
• 28" total depth
• RDSB of TBD Size

Here's the logic and thought process,
Integrated height of the stand+tank+hood (lights) becomes the driver. Asthetically and functionionally, the stand needs to be roughly counter top level. Skimmer height drives functional height of stand. I don't like hanging lights and the stray light inherent with pendant lights of any kind. Thus a hood is must. Lumen Bright reflectors plus 4-6 inches from water to reflector drivers hood height. The equation basically becomes this :

Tank Height = Max Total Stack (Stand+Tank+Hood) - Stand - Hood.

Stand and Hood are reasonably easy to determine with their drivers being known. Stand should be 3' tall. Hood should be 18". So Tank Height becomes Max Stack minus 4.5 feet

The question becomes "What is the maximum total stack that I want?"

Max Stack 6.0' : Tank = 6.0-4.5=1.5 = 18" Tank Too Short
Max Stack 6.5' : Tank = 6.5-4.5=2.0 = 24" Good asthetic Max Height, reasonable tank depth
Max Stack 7.0' : Tank = 7.0-4.5=2.5 = 30" Max stack getting big, nice tank depth

Thus, 24-30" is the right range. I want to maximize volume and I don't like the look of long/short tanks. Therefore, 24"/209gal is the lower end. Max Stack greater than 7 feet starts to get too dominant in the room. Therefore, 30"/262gal is the upper end.

Proportionally, 3:1 ratio of length to height with fixed 84" length gives 28" depth. I also like things the are even and proportional.

Current working dimensions are 84" length, 24" side, 28" depth. 244 gallon DT.

Will plan on 2" DSB with RDSB TBD.

How does that sound to everyone??? Any flaws in the logic??

M

 

BTW - At NASA, I REQUIRE my teams to be ruthless in their design reviews. One mistake can mean LOC/LOM... Loss of Crew/Loss of Mission. We take that VERY seriously. That background is also why I want to understand exactly what is driving parameters and decisions. I wouldn't "naturally" have come up with 28", but with the logic and thought process... yeah, 28" seems 'natural' after thinking about it.

Point is... please be ruthless with me. Don't hold back on your comments being 'polite'. Please let me know....

M

 

You use the term depth in 2 ways. Height and depth. So I want to be certain you are meaning what I am thinking.

If I am reading this correctly, you want the tank to be 28" tall, and 24" deep x 84" long, right?

If so, that sounds great. But personally, If I were you, based on my own plywood/ epoxy reef tank building adventure, I would go wider that 24" if you can by all means.

I made mine 30" deep, and I definitely wouldn't make it less than that. I eurobraced my top, that took up about 6" of open top space for lights (3" eurobrace all the way around). How are you bracing your top? You will need a center brace or 2 on a tank that long, probably 1 will work, provided that ties in with your lighting. If you run 3 halides, and have 1 brace in the center, that will give you headaches at best.

 

I would noyt be afraid of 3" of sand in the DT. Still gives plenty for the critters to play in. It will get turned over plenty.

I whole heartedly agree with your approach. Too often, people think of tank and nothing else. I don't want to use a step ladder, but I would never have a stand less than 3' again. Mine sucks, and I like the tank higher. Gives much more room when getting skimmers.

 

Yes, I meant 28" tall, and 24" deep x 84" long. I agree with you completely, but really can't do more than that in the room with the other furniture. So while, we are on the topic.... Explain "eurobracing" to me, please. I have read the term all over the place but not found any explanations. Could you post pictures of your eurobracing?

Thanks,
M

 

a few folks have alluded to my tank already but in case anyone still has doubts I can say that 400W MH's with apropriate reflectors can do a fine job over 48" of water depth.

I personally really like the look of a deep tank especially if it's located in a room with high ceilings. The deep tank does come with its own set of headaches though and it can be a royal PITA to have to work on things at the bottom of the tank... Otty wasn't kidding about the mask and snorkel thing. Also, it's pretty much impossible for me to ever get a fish out of here (even the ones that aren't moving any more can be tough to get out ).