Lighting: What is low, Moderate, and High?

[derek_s]

When I was setting up my tank, i bought a MH because I thought with it, I'd never need to upgrade. I would always be able to have anything I want, and never be short on light. I thought. Lately, I have found that almost all my corals need low to moderate lighting, so I have them near the bottom. So, I guess the real question is, aside from actually taking measurements, what is generally considered low, moderate, and high lighting? If I keep my tank mainly LPS and soft, should I even run a MH? Can I fill it better top-to-bottom if I go T5 or PC? Or with the right MH bulb, is the top ok for many corals?

Here is my coral layout currently (not all are actually pictured, but are there now). My tank is a 29 gal long, so about 18" deep, and my fixture houses 2 65W actinic PC's and a 20000k MH.

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[derek_s]

I am really just looking for suggestions on placement and lighting changes that will enable more options.

 

[humptrax]

PAR is the general term used to measure light output. Generally, higher the PAR, the more "powerful" your lights are.

More important than the power of the lights is the type of corals you're keeping. it seems like many of your corals are LPS or corallimorphians. IMO, most of your corals belong in the lower half (maybe lower quarter) of your tank. 250W of MH light should penetrate 18" pretty easily and my guess would be that your sandbed would measure a reading of 300-350 PAR, if not higher.

Corals have certain minimums as to how much light they need to photosynthesize. if you can't meet the minimums, corals might brown/die. If you far exceed the minimum, corals might bleach/die.

just look at your corals and see how they respond to being placed in different parts of the tank. also, remember to match the minimum FLOW requirements for your corals as well.

In my opinion, FLOW is more important in keeping corals than light (except with SPS).

 

[cgill311]

Be careful of the zenia and GSP. Those things grow like weeds and can take over your tank (especially zenia). For that reason, I won't keep either.

Regarding the lighting, you will be fine with the MH. Softies and LPS can survive off less intense lighting versus SPS, but that doesn't mean they will suffer under higher lighting. In my experience zoas and LPS will do just fine under stronger lighting. Just check out the tank where Cap Bay is growing acans, micromussa, and chalices in 3 inches of water under 1000W MH.

Basically, I think you will be fine. Just be wary of zenia plague. How old is you MH bulb?

 

[humptrax]

CGill311;145252 wrote: Regarding the lighting, you will be fine with the MH. Softies and LPS can survive off less intense lighting versus SPS, but that doesn't mean they will suffer under higher lighting. In my experience zoas and LPS will do just fine under stronger lighting.

from my observations, blues and purples do better with lower light regiment. Oranges, reds, and greens seem to respond better to higher light regiment.

 

[derek_s]

Well, all my corals seem to be happy except the trumpets. Some I just got, but my others I have had for a month now. They do open to feed, but they never seem very puffy and nice like the day I bought them. I have tried them on the bottom with low flow for 2 weeks, and just recently moved them to the middle with moderate flow (current location in picture). How long should you wait for them to adjust before you deem a spot 'undesirable'?

humptrax;145250 wrote:
In my opinion, FLOW is more important in keeping corals than light (except with SPS).

You know, that's a whole different question. Since you brought it up, I will ask. What is high, moderate, and low flow? Is it measurable? I mean, what constitutes HIGh flow, asn opposed to LOW flow.

My tank is running a Mag 5 return pumping up ~3 feet, and a Koralia 1. I would consider my overall tank flow to be low, with spots near the front of the diffusers and koralia high flow. Is this a correct assumption?

 

[cgill311]

LPS seem to like moderate intermittent currents. As such, I'm running my 30G tank with a Mag 9.5 return to a SWCD and a hydor rotating output (3 outlets total, with 2 on at any point in time). I'm trying to simulate the chaotic wave and flow patterns that exist on natural reefs.

I haven't experimented around with other flow patterns b/c this works well for me. Hopefully the more experienced will chime in.

 

[derek_s]

Yeah, I have considered a SWCD. Wow, a Mag 9.5 in a 30 gal?... I thought my mag 5 was killer for a 29 gal. Should I be looking at upgrading to a higher GPH? I would assume a SWCD will actually increase the flow rate since it will be somewhat doubled at each diffuser.

 

[humptrax]

start here:

http://www.advancedaquarist.com/2008/1/lines/view?searchterm=laminar%20water%20flow">http://www.advancedaquarist.com/2008/1/lines/view?searchterm=laminar%20water%20flow</a>

i think it was a 4 part article. It's really good.

flow again, rather than looking at it as high or low, is something that you'd want to regulate based on the types of corals you're keeping. generally, it's better to have high turnover rates inside your tank rather than outside (to the sump and back).

 

[reefknight]

I have ran my 30 cube w/ a SCWD for about two years. Mine is plumbed from the sump, through the rear wall of the overflow, branching to two intank returns that are "y'ed", this is all powered by a PanWorld 50x pump (590gal). On top of that I used to run a Maxi 600 and 900 w/ hydor flo's, then switched to a Koralia 3 and a Tunze 6055 w/ single controllor. I have to watch the placement of certain LPS as they don't like that much flow. Sps love it!

I agree w/ the above mention of Xenia, WEED! GSP have never taken over my tank though, but be carelful as I have seen it happen.

Your're lighting is fine, my prop tank has a single 150W MH, w/ Phoenix 14k lamp and will grow anything. Some of my corals grew better under it than my 250W MH 10k. I like the 14k spectrum as well and no need for actinics.

vette, a SCWD will actually reduce your output somewhat. I used to know the percentage of reduction but not anymore. Mine is two years old and I have had no issues with it. Alot of people really bashed these on R/C, but again my experience was different.

 

[cgill311]

corvettecris;145287 wrote: Yeah, I have considered a SWCD. Wow, a Mag 9.5 in a 30 gal?... I thought my mag 5 was killer for a 29 gal. Should I be looking at upgrading to a higher GPH? I would assume a SWCD will actually increase the flow rate since it will be somewhat doubled at each diffuser.

Yeah, a lot of people think I'm wierd for running a mag 9.5 through my sump, but it works well for me. I have a valve installed immediately after my return that I keep about 90% open to restrict the flow a little. There are also loses with head pressure, SWCD, and hydor. Hydors and SWCD's use energy from the water flow, turning it into mechanical energy to drive the device, so there is always a pressure drop (or drop in flowrate) across the device. So since my 9.5 may be overkill by itself, the water movement devices and head reduce the flow to a level that works great for my tank.

 

[photokid]

the only issue i have with the SWCD is you can not control the rate of alternation with out changing the amount of flow.

 

[cgill311]

photokid;145321 wrote: the only issue i have with the SWCD is you can not control the rate of alternation with out changing the amount of flow.

Mine switches every 10-15 seconds. Seems pretty reasonable.

 

[reefknight]

The more gph the faster the switching rate, if its not fast enough throttle up your pump. In turn too fast, throttle it back.

 

[humptrax]

photokid;145321 wrote: the only issue i have with the SWCD is you can not control the rate of alternation with out changing the amount of flow.

no issues with clogging? one piece of sand and BANG! the whole unit goes to crap and turns into one giant restrictor.

 

[derek_s]

So, I red the article. It is pretty helpful, but basically, if I have a 29 gal that is going to be mostly LPS, what is a good rule of thumb on water turnover, both closed loop and return? What is the best way to achieve this (maybe % wise, like 30% sump return, 70% closed loop)?

 

[cgill311]

humptrax;145331 wrote: no issues with clogging? one piece of sand and BANG! the whole unit goes to crap and turns into one giant restrictor.

I've been running mine for over 1 year with no problems, and I've never cleaned it.

 

[cgill311]

corvettecris;145476 wrote: So, I red the article. It is pretty helpful, but basically, if I have a 29 gal that is going to be mostly LPS, what is a good rule of thumb on water turnover, both closed loop and return? What is the best way to achieve this (maybe % wise, like 30% sump return, 70% closed loop)?

Closed loop systems are something you build before you sent up your tank. Most people prefer to drill their tanks for the CL. I don't think you need one for a 29G tank.

Do you have a controller? If so you could put the Korallia on a wavewaker setting. If not, you could replace the Korallia with a maxijet + hydor. Or keep the korallia and put the sump return on the hydor. Or T off the output into several outlets in different directions. If you're not into current directing devices, try aiming two powerheads straight at each other from opposite sides of the tank. The whole goal is to create some erratic water movement. Just play around with what you've got.

 

[dannybradley]

humptrax;145257 wrote: from my observations, blues and purples do better with lower light regiment. Oranges, reds, and greens seem to respond better to higher light regiment.

That's true because red is the weakest wavelength and is quickly filtered out, whereas blue is the longest and pentrates deeper. Coral that evolved deeper down were never exposed to those wavelengths of light, and therefor never developed a need to reflect it back to protect itself. It absorbs those colors and probably shouldn't be exposed to them in high levels as it has no protection from them.

As I ramble more about this is gets me thinking about one thing Dana Riddle said at the meeting- 'Coral bleaching is more likely the coral expelling zooxanthellae to uptake a different species that can better deal with the environment it is exposed to.' - such as when a coral exceeds photo saturation reaches the point of photoinhibition.

 

[derek_s]

CGill311;145478 wrote:
Do you have a controller? If so you could put the Korallia on a wavewaker setting. If not, you could replace the Korallia with a maxijet + hydor. Or keep the korallia and put the sump return on the hydor. Or T off the output into several outlets in different directions. If you're not into current directing devices, try aiming two powerheads straight at each other from opposite sides of the tank. The whole goal is to create some erratic water movement. Just play around with what you've got.

Seems like some pretty simple solutions. I do have my sump return T'd off on both top sides of the tank, but with no current switcher. They just flow equally, both kinda aimed at the front center of the tank. About how much flow gph wise should I aim for?