Flow question for upcoming 210 gallon build

[IANick]

Ok, my first post here. So I hope this works...

I'm planning a ~210 gallon build for my home office (73.5L x 23.5W x 32T with 0.75" glass... Starphire on 3 sides). Custom in-wall cabinetry was installed when the house was built. My office is my refuge, so one of my main goals is as close to a dead silent setup as possible. As such, will be running a bean system through a Calfo style coast to coast overflow. The sump will be below the DT inside the cabinetry. Pumps and skimmers etc will be located on a shelf below the office floor in the basement to reduce noise.

I'll be running a closed loop with an oceans motions 4way (aesthetics and noise reduction behind this choice). My thinking at present is to have three intakes for the CL on the back glass. 2 returns will also be on back glass and will each blow through a "y" fitting thereby creating four separate streams. They will blow through the rockwork from the back to the front of the tank. 2 more returns will be drilled through the bottom glass at the front of he tank. They too will have y fittings. These will be angled up at about 45 degrees to blow up and over rockwork toward the overflow. The returns on the overflow will blow down the back glass. This "rolling" motion seems to be the preferred setup method by Paul at oceans motions. So far so good. The problem arises in that I'd like to get 40x turnover in the tank, and this would imply about 6600GPH through the CL (assuming about 1800GPH through the overflow/sump). Is 6600 GPH through the described CL doable or realistic? Especially bearing in mind I want a quiet setup... I'd think the required pump would be a monster and certainly make more noise than I'd want (even if housed below the office floor on a high shelf in my basement).

I'd like to avoid power heads if possible... But maybe I have to supplement the flow with them. What do you guys think? Yes? No? Consider a 2nd CL? But then the plumbing starts to get a bit crazy. Any thoughts are suggestions would be greatly appreciated.

Nick

[IANick]

No thoughts anyone? Although I must say that after pondering nonstop the past 24 hours that I'm leaning toward keeping the described closed loop powered with a super dart gold pump and augmented by two tunze 6155's set more or less at the center of each side panel. I'm thinking about 1800GPH with a super dart gold for the main return (after accounting for ~10' head loss to the high basement shelf); perhaps 2200GPH through the super dart gold on the CL; and 2500 - 3000GPH for each of the tunze 6155's (running at less than full output for noise reduction purposes). I guess I'll have to find a creative way to hide the tunze in my aquascape (which I have already started to develop ideas for).

If no one has any other suggestions on my initial inquiry, how about thoughts on this proposed setup?

Nick

[dave.m]

Just a couple of suggestions:

Your tank is too narrow. It should be at least as wide as it is tall, if not wider. I think 32" tall is brilliant, but you will have issues reaching the bottom.

Branching things out in Y's actually reduces the power of the individual returns. If you insist on using Y's then put eductors on the ends of all of them to increase flow (you can almost never have too much flow). When planning your returns, think in terms of creating a gyre flow round the tank so that bottom water constantly gets pushed to the top in a barrel-like flow.

Dave.M

[IANick]

Hi Dave,

Thanks for the suggestions. I agree that I would like the tank to be wider but, unfortunately, the custom stand and cabinetry was built into the wall of the office when we built the house 3 years ago (RocketEngineers stand design... custom in wall cabinetry surrounding it floor to ceiling... ceiling about 11' high). Now, I wish I had gone 30", but its too late. Could I do a little reconstruction? I suppose so, but would prefer to avoid it. Any others have thoughts on this front? Myself, I'd like the tank to be wider for aquascaping reasons, but I had never really considered the width to be too narrow for any other reason than this aesthetic preference. Am I missing something? Do my dimensions somehow inhibit flow? I really want to make sure I don't make any choices (I won't say mistakes!) from here on out that I will regret, so I am planning, planning, and planning. So any thoughts are welcome.

With respect to splitting the CL returns into y's, I didn't realize this would reduce flow. How so? A little added friction perhaps? Is the flow reduction material?

Finally, I agree with your suggestion to create a barrel roll effect pushing the water toward the top of the tank. That is what I am attempting to achieve with the returns placement (2 on back panel shooting forward across the bottom of the tank; two in front shooting up to the overflow; and two main overflow returns shooting down the back of the tank from the interior calfo), based upon the advice of Paul of Oceans Motions provided. Returning to your first observation that my tank is too narrow, does that comment somehow pertain to the fact that the front returns will have to be angled higher than 45 degrees to push water to the overflow because of the narrower width of the tank (based on my recollections of trig, it would be about 55 degrees assuming the front returns are at the extreme front edge of the glass, which they won't be... probably 3 or 4 inches in from the glass, so probably shooting up at about a 60 degree angle)?

Anyway, thanks again for the input! Any and all follow-up by you or others would be appreciated.

Nick

[dave.m]

Don't ask me to do math. I don't do math. I am a math retard.

The taller and narrower the tank the less surface area you have for gas exchange/oxygenation of the water. Also, as you have pointed out, wider tanks have more possibilities re. layout and aesthetics. I currently take care of a 36" tall tank that is only 24" wide. I can assure you that design possibilities are extremely limited.

The output pipe size of the pump is what it is engineered to push. When you split this up, the area of the outputs are usually greater than the area of the pump's outward pipe; flow is much reduced, but I don't know the engineering calculations to show the how or why. Just don't do it. Or else. ;)

re. direction of CL outputs, a Calfo-type overflow needs something aimed right at it to achieve the same sort of surface turbulence achieved by a crenelated overflow. This turbulence is required to break up the oily layer that forms on the surface. If you haven't read the 3-volume Reef Aquarium series by Delbeek and Sprung I suggest you do so. Although a bit dated in some ways, they outline what the problems are and suggest various ways to resolve them. What solution you come up with can be entirely yours, but understanding what the problems are in the first place is key.

HTH

Dave.M

[IANick]

If you haven't read the 3-volume Reef Aquarium series by Delbeek and Sprung I suggest you do so. Although a bit dated in some ways, they outline what the problems are and suggest various ways to resolve them. What solution you come up with can be entirely yours, but understanding what the problems are in the first place is key.

HTH

Dave.M

No, I have not read this. I'll have a read. Thanks.