fishyjoe24

what about marc who owns melevs reef. he does acrylic sumps, and works with acrylic might see if he could build you a tank...

walterk

Thanks, but I gave three company contacts to my LFS to get bids. That's what I'm going to have to go with.

Michael

"Spiral CFL's, 23 watt (with bell):
1 bulb 29
2 bulbs 54
3 bulbs 76

Spiral CFL's, 14 watt (with bell):
1 bulb 20
2 bulbs 35
3 bulbs 46

CREE LED's, 9 watt, 60 degree, DIM option:
1 bulb 48
2 bulbs 57
3 bulbs 65"

I wonder why increasing the number of LED lamps gives much less increase in light than increasing the number of CFLs?

Using 3 23 watt CFLs gives a 260% increase over 1 23 watt. 3 LEDs only give a 135% increase over a single lamp. This seems counter-intuitive. I can understand why 3 lamps don't produce exactly 3 times as much light because of scatter and other inefficiencies. But why do 3 LEDs give realtively little improvement over 1?

walterk

I think the answer is that the LEDs have a more concentrated and focused beam.

The CFLs (in a bell) provide a greater overlap of light. When you turn on lamps 1 and 3, the space between them has a warm glow of light.

The LED bulbs are set at a 60 degree spread. If they were set to, say, 80 degrees, you would have I higher degree of the lights overlapping. When you turn on lamps 1 and 3, the space between them is pretty dark compared to the CLFs.

The CFLs give more of an even, "softer feel." You do not have the harsh shadows that you do with the intense LEDs.

The bells provide for a lot of restrike for the CFLs, so the light must be exiting there at a lot more angles than the LEDs provide.

At this point in time, I'm not sure which I like better from an aesthetics viewpoint only.

Once I get the tank, I'm going to have fun checking out the difference between the bulbs in shimmer, plant growth, etc. Should be interesting.

Michael

Thanks! I am a big fan of CFLs, but have not used LEDs. I will be very interested to learn your results.

walterk

Good to hear that you are a big fan of them. I might end up going in that direction in the end. I wanted to try the LEDs as well. We will see how this goes once it is all set up and the lights go through their paces with plants in the tank.

walterk

I'm getting a quote from A.G.E. today on the tank. Already have one from a company in Georgia. Again, Planet Aquarium was a no-go because they do not do acrylic.

The guy at A.G.E. warned me that because of the rise in petroleum, the acrylic will cost more. Just how much more I will find out. The quote from the guy in Georgia seemed reasonable, but shipping is a killer. In my thinking, he likely does not produce tanks in the same volume as A.G.E. and might have acrylic stockpiled (that will not be effected by the recent price increase). That said, I would be willing to pay a little more for the product that A.G.E. puts out.

Niko -- you absolutely recommend a U-shape flow? This tank is very long at 8' and rather shallow at 12" of water. I'm going to push the water with a canister filter rated at ~440 gph in ~84 gallons (and perhaps also use a circulation pump). I know you promote even more filtration flow, but I'll have to address that later if I want to do so. I will have sand as a substrate and I don't want it to be pushed around too much.

The canister will be raised so that the tubing will be rather short. Sponge prefilters will be used. I plan on having medium-pieces of lava rock for biological filtration in most of the filter. I currently have these pieces in my 46 bowfront.

Holes will be drilled in the top bracing once I determine which company I'm going with and finalize the filtration configuration. Right now, I'm planning on having the U-shape flow.

Question for anyone: Concerning the dynamics of the flow in the tank, what might I expect?

There will be little obstruction, with streamlined driftwood and smooth rock. The tank is quite shallow. My thinking is that the turbulence will be greater in a shallow tank. What will happen when the water is pushed on the surfaced to the far end?

I think I will initially fill the tank with water (no driftwood, rocks, sand or plants), drop in some dye and observe the flow at a lower rate. Then I might increase the flow with small solid items and watch where they end up.

niko

Experimenting with a dye will not really help you if the tank has no decorations and especially no plants.

From what I heard/saw in the last few months from people that actually can show striking clean planted tanks the flow does not have to be U-shaped. Some of these guys even use a spraybar (max. turbulence). But everybody agrees on one thing - the plants must gently sway in the current. To me there are optimal ways to do everything and there are ways that work but are not optimal. If a dirt particle is floating endlessly in the tank and never makes it to the filter that is a problem (chaotic flow). A problem with a strong U-shaped flow could be the flow rate - it may be too high if you do not use an outflow that produces a wide and gentle powerful flow out.

Also please do read the article that I referred to the other day - the one about the Redfield ratio. Basically you must have N in abundance (best thing is if it comes from the substrate). Then the P becomes the start/stop button for everything. Keep the P about 0.1 and algae has very little chance to try something funky. Staged light plays a huge role in the stability of the tank. That is how ADA does it: P as a limitation factor + Infinite N supply + Staged light. Of course - it all needs to be done with proper maintenance (biofilter, water changes). I suggest reading about Redfield and stressed on the staged light schedule because they basically makes the decision about the water flow & pattern more or less secondary. Once again - if the plants move in the current you are fine.

walterk

I understand what you are saying. Why observe something that will change as soon as you add things to the tank?

Still, by observing the flow without driftwood, rocks and plants, it allows you to plan accordingly. Once I see the flow, I can place the three pieces of driftwood.



Thanks. This helps.

Great!

walterk

Ordering the tank from A.G.E. on Friday. Should arrive in 4 - 6 weeks.