is 30 gallon "standard" the standard?

[bamse]

Hi everyone,
I am working on building a reeef system based on a 36x12x16 size tank.

It seems to me to be a good choice for a 30 gallon:
- it is shallow (allows better illumination)
- it has decent floor surface for the volume (good dsb, and coral deployment)
- it is like a display, allowing for better deployment and viewing of corals (I don't need to stack 'em, that might be creating overshadowing or overgrowing issues over time)
- most frag tanks I see in LFS-s are like this, so what is good for a chip must be good for the tree

But most of the information sources are re(e)ferring to shorter and taller 30 gallons tanks. When people are talking about 36" equipment, they usually imply higher volume tanks like 40 gallons.

Am I missing something about this shape format? Is this not the "standard" 30 gallon?

Thank you

[Chiefsurfer]

Well, frag tanks are generally very short, because all they have in there is frags. Meaning a nice flat level surface to place the frags on/in(usually eggrcate) and there is no need for too much water above and below. This is nice, because the plug is it's surface, and the plug sits nicelu in the eggcrate, and they can be spread out pretty evenly. The less water that light has to pass through, the more PUR(actual light that corals need) is allowed to get to the corals. In our situations, this is usually not desireable in a Display tank.

Reason is this. Usually people reccomend a minimum of 1lb/gal, and if it is decently stocked, usually higher. What I would reccomend for a tank that size would be near 45lbs of LR on an average stock. Once you add sand(and a lot of sand if you want to do a DSB) and rock, you will have little to NO room left above your highest rock, meaning you have little room for your frags/corals to grow up, which makes it tough for sps, as they like to be high on the rock, and grow up. With a DSB in that tank, you automatically take 4" out of the depth. Then you're working with only 12" of height to the tank. In my 17" tall tank, I have maybe 3" from the top rock to the water-surface. I do have 40 lbs in a 20 gallon tall, but maybe 45# in a 30 would be 10" tall rockwork(just guesstimate) leaving only 2" above the tallest rock. This doesn't allow for much creativity or interesting shapes, caves, etc in the rock.

The 40 Breeder also gives you a bit more front-back depth, which gives you even more aquascaping ideas.

If you are going 36" long, do yourself a HUGE favor and get the 40B.