OK! Enough chat...Starting a 1000g+ Reef

[tinygiants]

<a href=showthread.php?s=&postid=6593186#post6593186 target=_blank>Originally posted</a> by jnarowe

I could make the base shorter but I do have those large BHs to install as well as needing significant strength to hold up the skimmer. And I am using extruded acrylic.

I don't think I can get 20gpm. In fact I am guessing around half that. I really appreciate your input and I can't believe my luck in meeting a local reefer who can share advanced technical knowledge of fluid movement!

Your compliments are nice, but undeserved. I do not know the formula for calculating the through put of a 1 1/2" BH with a 4 - 5" head on it. I can tell you my 1" BH passes well over 10 GPM. A 1 1/2 BH is nearly double the area of a 1 BH. With that thought in mind, it is entirely possible to gravity drain 20 gpm from a 50" height to some height lower than 50".

Why use a base design? Why not make the entire thing a mixing chamber? More volume is better when you have a beast to skim.

Dale

 

[jnarowe]

That's a really good question and I have been asking myself it over the last week. So why do all the commercially produced ones have a base? My assumption is that generating the bubbles in a larger area and then funneling them up the chamber makes for a higher concentration of bubbles in the reaction chamber. What do you think?

 

[tinygiants]

I think they can use cheap BH's on the flat panels, and they have a nice square base for support. The commercial ones you speak of are all beckett and NW right? The air system is directly tied to the pump system. The better ones have the pump for the air seperate from the feed. There really is no advantage to the box then the tube. In your case, you need volume. You have no intention to tune your water level to even with the bottom mixing chamber. That is the usual advice I have seen with skimmers of this design. It allows for mixing in the box and uses the attached area as the foam riser. If anything, I would bet the step adds turbulence to the foam as it rises through the non transitioning opening.

Dale

 

[jnarowe]

I didn't quite follow that last part. But remember when I showed you the Prizm skimmer on my rock tub?

How about this? I make the entire skimmer 16 x 14 (saving some time and effort) and install a baffle to route the bubbles back into the downflow of water.

My main concern is actually not being able to create enough bubbles to fill the boddy without some kind of step.

 

[prostaff]

<a href=showthread.php?s=&postid=6589517#post6589517 target=_blank>Originally posted</a> by tinygiants
If the overflow is 50 " high, it can not fill a skimmer to 60 " high by gravity. The highest the skimmer could be is 50". Yes a gate valve can be used to control water height.

Johnathon will need to process in the neighborhood of 20 gpm in order to skim his tank 2 times a day. He is going to need all the height and volume he can get.

Dale

Duh. what was I thinking? I never even thought that the skimmer could be taller than the overflow especially with a tank that big. I just assumed the tank would of course be higher than the skimmer hence the term "gravity flow". Thanks for clearing that up dale.
Jonathan, Dale does have a point about the boxless skimmer. I built mine with 10in diameter tube, no box base and a riser and collection cup and that sucker outskims my etss. I am having another one built for the big tank in the same manner but larger diameter tubing or pvc using 3 or 4 sedra 9000 pumps for recirculation

 

[jnarowe]

So then the question is how much air will I really need...oh here we go again! Well, maybe I will build it with no base box and see how it goes. I can always change it later. I have 1-1/2 sheets of 3/8" acrylic so I should be fine. Just need to make the skimmer, top-off tub, kalk and calcium reactors. Yikes!

Anyone want to come over and sniff some glue??

 

[tinygiants]

Do you really want to know how much air you need, or are you joking?

You know I can model it and get in the ball park.

 

[jnarowe]

I wouldn't joke with a man that could make hazardous waste come out of my toilets!

I do want to know how much air I will need. Remember that I am using two manifolds with four 3" wood stones each. Measurements would be 16 x 14 x roughly 48-50 inches for main body assuming that I go with no box bottom.

What do you think?

 

[tinygiants]

Remember, you asked.

16 X 14 Skimmer X 50 " tall = 48.48 gallons.
Air feed 5" from bottom
Average bubble rise rate = 6 inches/second (this is what my fine pore stones produced)
Bubble dwell time = 7.6 seconds
Air volume needed to maintain 13 % air in water = 6.64 CFM @ 2.1 PSI

I am sure this number is off by a little, but I bet you a Coke, it is close.

Dale

 

[tinygiants]

Seeing that volume made me think. Why not just get one of the drums with a removable top from usplastic.com
http://www.usplastic.com/catalog/pr...e=USPlastic&category_name=25&product_id=15706

You could get some uniseals from aquatic eco for all the plumbing. You can modify the lid to be the riser with a skimmer cup.

Dale

 

[jnarowe]

Thanks for the work up Dale! That's not too bad. I wonder which pump I should get to have a good margin to spare?

About the barrels: Well that would be just too damn easy now wouldn't it! I know you told me about where I could get them used also. I may actually use one of those barrels for kalk.

If I run into trouble with my skimmer, I can always try that.

 

[Morgandy]

<a href=showthread.php?s=&postid=6482199#post6482199 target=_blank>Originally posted</a> by jnarowe
I muttered to myself something about being married to a nut, and went back to work on my 8' lng overflow.

What a DREAM come TRUE! I'm finally at last a fly in the men's-only smoking parlour!!!! :lol:

You guys are ALL so busted, and totally cracking me up . If I weren't a totally addicted reefer, up at 2:30am reading RC and great tank threads, I'd ring all your wives up to FINK on you.

But, regardless of the banter, I can't wait to see this thing up! It looks like it'll be awesome, and I have to live vicariously through others' large tanks now (my 210 is gone 4 wks now).

Oh, and don't censor yourselves cuz of me!!! :rollface:

 

[jnarowe]

now I have to watch what I say!

what happened to your tank?

 

[jnarowe]

BTW Dale, essentially your calculations point to about 300W of air pump. I wonder if it might be more efficient to go to beckets?

 

[tinygiants]

How much air can a becket handle before it giant bubbles on you? I am betting it will take between 4 - 8 becketts for a skimmer body of that size. This is just a wild number out of thin air. I have not measured what a beckett is capable of handling. I have a nozzle if you have a pump. We can hook it up and see how much air it pulls.

In my mind that will be more than 1 pump to run it. Even Spazz's NW Dart only puts out 2.25 CGM with a supercharge. His bubbles do behave better though. I just ran the numbers from Spazz's dart skimmer, it is what you need. His dart supercharged or 2 of them non supercharged.

Dale

 

[jnarowe]

I have a luft pump right now. I have seen you refer to "NW" before. What does that mean? That Dart draws a lot of juice too. It would be 320W for 2 of them. What is a "supercharged" dart? Never heard of that.

 

[tinygiants]

Look up Spazz's Needle Wheel Dart DIY thread. He made a needle wheel for his dart pump. From my calculations his bubbles are the most consistent. His bubble cloud averaged 1.64 inches / second. My smallest bubbles were better than that, but my average was nearly 6.

Supercharged is what spazz called installing an air pump to force feed his needlewheel. The drawback of needlewheels is they lack the pump power to overcome a lot of head. His NW does overcome your head pressure without a supercharge, but the volume is not enough. it would take 2. His supercharged version is about perfect for your volume.

dale

 

[jnarowe]

Thanks Dale. I read the thread and it may be the way to go. It sounds like he has been able to lower the electrical draw by building this combo pump/needle wheel. I sent him a PM.

It also sounds like has removed the original impeller and replaced it with a slef-made needle wheel. No pictures of it that I could find, so maybe he will post some.

What's your gut feeling as this relates to my project? Do you feel I should skip the air stone skimmer and build one of these needle wheels? I had originally wanted to do the air stone skimmer to lower electrical usage, but it appears that may not be true.

 

[tinygiants]

I want one of his NW pumps. He is not posting pics of it yet. That may come in the future. Right now, I know he is testing it.

Dale

 

[jnarowe]

It just occured to me that I never posted what I used for overlow combs. Here's a pic. They are about 13" long and I put 6 along the back of my tank. Since they are removable, they are easy to clean.

Got them on ebay from Aqua Cave cheap!