18,000k Light

[colin779]

Is that to strong of a light for a 20g reef tank?

My light currently is a t5 ho 2*24w , with an actinic and a 6700k full spectrum.

I am having some issues with algae growth (hair algae) even though i do weekly water changes and am problably starving my 2 fish. All water parameters test ok, 0 nitrates, phosphates and ammonia, and all water changes are done with RODI water.

Based on what i have been reading i was beginning to think that the 6,700k bulb is just to low a spectrum and can be attributing to my algae growth.

Any comments/suggestions/anything at all helpful would be greatly appreciated.

 

[Krish]

An 18K bulb will be really blue. Not sure what you mean by it being too strong for a 20g reef tank, but there will be no issues in using it. The only problem you may have is that if you have corals, they may grow slower depending on the par rating of the bulb, but other than that, you'll be fine IMO.

As for the algae issues, although your test results look great, it could still mean that there are excess nutrients (phosphates, nitrates etc) in your system and may be bound up in the algae which it is using to grow. Algae won't just grow on it's own so there has to be something in your system providing it with food. A bulb alone won't just do it. How long has the tank been up? Give us a bit more info on your system so we can know which direction to steer you in. Changing a bulb IMO probably won't solve the algae issue

 

[lizardarm]

How old is this setup? Also, how many hours a day are the lights on? My understanding has always been (and it may not be correct) that the 6700K kelvin lamps are great for growing plants but not much else where reef aquariums are concerned; so switching lamps might help. If this is a newer setup though, you might just want to give it some time and be diligent on manually removing the algae.

 

[Scooterman]

My understanding has always been (and it may not be correct) that the 6700K kelvin lamps are great for growing plants but not much else where reef aquariums are concerned; so switching lamps might help.

Not true, actually you would get better performance with a 67K lamp over the higher K lamps In general, mainly because the PAR performance it typically way better & more punch into the depths of the water. The reason why you don't see much of it in the Reef tanks is because of the looks, they are very yellowish.

 

[colin779]

My system has been up since October, but i moved back in the beginning of Fubruary.

When i moved is when i changed my lights to the t5 ho lights.

I am runnning a skimmer (hang on) that uses a maxi-jet 1200, i have 3 power heads, one at 170 gph, 160 gph (auto rotating head on this one), and a 90 gph. My Filter also moves 130 gph.

Is all of this ok?

That is what i have heard about the 6,700k bulbs, it is a little on the yellow side, but i am getting excellent growth on all of my corals. I think i will be returning the 18,000k bulb today, i put it in last night for about half an hour before my lights went out and the bulb actually looked really red, it was bad looking. With only two bulbs im thinking it would be better to just keep it the way i have?

I will just have to remain diligent in my manual removal of the algae. The hermits appear to be starting to make a noticable differnece over the last week or so.

I will post a few pictures when i get home from work today.

 

[xfisher]

bulb color

I use two 20k 150's they are blue,but don't turn blue until they warmup.Also the bulb manufacture says you won't get the true bulb color until 100hrs. of burn time,Even still if you had your bulb on long enough for it to warm up I would say something is wrong w/ that bulb 18k shouldn't look red it should be bluish,I would xchange it cause blue color may sacrifice some growth but makes everything look much better in my tank

 

[OldFishMan]

Hello;

This is a good place to start your research:

http://www.thekrib.com/Lights/

And, here is a good explanation of lighting, plants and PAR value etc,.

http://www.sunmastergrowlamps.com/SunmLightandPlants.html

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