10k vs. 20k DE Comparison Shots

[Reefland]

Hey Gene!

There isn't really any difference at this point; which is why I posted the picture. Maybe after another 100 hours or so we'll see some difference.

Scott Z.

[Reefland]

Here are some updated pictures of the 20k AB bulbs on our 75 gallon reef after 2.5 weeks of use.


******THIS PICTURE IS THE DAY THEY WERE ADDED******

**********************************************

[zhenya]

Looks good,Scott. Not as blue anymore either. I see you have a p/head waaay down there ;) Does it help to keep junk in suspension longer?

Looks very clean

[Michelle]

Looks really nice,Scott. However, I did not notice much difference between two pictures, probably due to my bad eyesight
I did notice that you had moved one of the corals a bit higher,though ;)

I don't think my eyesight is bad, but it looks great to me without all that red algae!!

[Reefland]

Shhhhh. don't say red algae!

Gene,
We have 2 powerheads at the very bottom of the tank and it does help keep the waste from building up but there is still one spot that it does that I siphon out when performing water changes. There is the 1 you see and there is one along the back on the right side of the tank.

Scott Z.

[zhenya]

Shhhhh. don't say red algae!

Michelle,
I only commented on the light bulbs that there was no difference between some earlir pics.I agree that tank looks great and absence of the red a....(shhhh) definately has something to do with it.

[Poseidon]

Nice shot of the photographer!!!

In the reflection!!!

Looking great Scott, I'm sure the lack of any RED stuff.... has a lot to do with it...

[Reefland]

Nice shot of the photographer!!!

In the reflection!!!

Looking great Scott, I'm sure the lack of any RED stuff.... has a lot to do with it...

We'll it don't match Gene's reflective shots but hey.....

Scott Z.

[oakie]

a few posts up on this thread it mentioned that actinics wouldn't be needed with the 20k - is that the case?

[Reefland]

Hi oakie, Welcome to Reefland!

The use of actinic supplementation is up to the eye of the beholder in any application. If the main lights are intense bulbs (mh) that range in between the 6500k and 20k range, the saturation point of the coral is going to be met. Actinic supplementation provides blue light which is thought to look more natural.

It is my opinion that 20k bulbs do not need actinic supplementation to be asthetically pleasing.

[oakie]

Thanks Scott.

I had just replaced my 14k with 4 of the 20k - wasn't seeing much difference with the actinics on, so I thought I'd shut them down - I was running 4 of the 6 footers. Or probably have them run 2 hours at the start of the light cycle and maybe another 2 hours at the end of the light cycle.

[zhenya]

We'll it don't match Gene's reflective shots but hey.....

Scott Z.

Good thing you were dressed,Scott Remember my pic with the roll of paper towels seemingly stuck in the tank? :eek3:

[Reefland]

Thanks Scott.

I had just replaced my 14k with 4 of the 20k - wasn't seeing much difference with the actinics on, so I thought I'd shut them down - I was running 4 of the 6 footers. Or probably have them run 2 hours at the start of the light cycle and maybe another 2 hours at the end of the light cycle.

Now I think that the additional light itself it helpful, but not necessarily the actinic. ;)

Scott Z.

[oakie]

Scott, do you mean add more MHs?

Not sure I understood your last comment.

[Reefland]

What I meant was that running the actinics for the additional light output is always helpful, but the fact they are actinic has no relevance. Could be Daylight lamps or actinics, at that point your just using them for extra light.

Scott Z.

[dougc]

I guess I will find out soon what kind of color shift happens going from 20k to 10k. I just got some frags last weekend that have been growing under 20k. I am running 10k Ushio DE bulbs along with 4 5-foot actinic VHOs. My tank is also deeper than the tank these corals were in, which may balance out the difference in PAR. I took some pictures, with and without the MH, but I did not upload the pics taken with MH yet. Here are a couple with just the actinics. I will get the MH pics uploaded tonight.



And:


I will keep taking pictures over the next couple of months for comparison.

[LazyReef]

Just my opinion, but, I think to much emphasis is placed on PAR. Some flourescing pigments have evolved to protect corals, but most have evolved to allow corals to compete at lower depths where blue and violet light travel furthest. The pigments convert violet light and UV to spectrums that can than be used by the zooxanthellae. Some Pavona (which are hermatypic) live very deep and fluoresce under UV. I have taken many photos with UV only light at night at 80 feet in Tonga and then followed evolutionary lines to see where fluorescing corals have devloped.

So I would not worry about the decrease in PAR but would look to see how the corals color up to adpat to the blue-violet-UV. They may grow even better depending if they are fluorescing corals