LIGHTING QUESTION

Riekert Botha

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I am setting up a cold water marine system and I am baffled by the whole question of lighting.

Plants and coral need light to grow. But, as the argument goes, they don't only need light to grow - they need the correct intensity of light. However, most people have tropical aquariums that accommodate intricate tropical corals and plants accustomed to a paradise-like environment. A cold water marine aquarium is a total different kettle of fish!

I suspect I might need half the lighting recommended if not less. Here's why:

1. My friend in Stilbaai keeps a healthy cold water marine aquarium without any lights. The plants in his system do not wither.

2. As a scuba diver I am amazed to see the abundance of rich plant life at 30m and 40m depth where hardly any significant light penetrates. For most of the time we need diving torches even when diving in daytime. We frequently encounter sea ferns and other plants much taller than a human. They florish under low light conditions!

I cannot fathom why a 70cm deep system needs thousands of Rand's worth of lights. Does anyone know?
 
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RiaanP

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For a cold water system, I would not go Metal Halides at all. Although they give a lot of punch, and today with leds taking over you can get them secondhand for really cheap. The issue would be the heat they transfer into the water, that would force you to use a chiller. Or bigger chiller.

The same applies to T5 units. The heat given off is a lot less than MH. But because you mount them a lot closer to the water surface and they give off heat across the full length of the unit. They have the same impact as MH.

Advantage with LED is that although they do give off heat in front of the leds, the distance you mount the system is much higher. Therefor you get no heat transfer into the water. For a cold water system that would be a big plus.

As a side note, although off topic. Run external pumps wherever you can. For example the return pump. External skimmer would also help. External powerheads like Vortech are expensive, but as the motor part is outside the tank it also helps a bit.
 

Adrian B

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Riekert I've done a lot of cool or cold water diving. Almost all those "plants" you refer to bellow 10m or non photosynthetic corals and encrusting organisms that feed on suspension and plankton type stuff due to the low light levels you refer to.

Especially applies from Arniston eastwards. West of Arniston you can find kelp growing in 20m of water

Would imagine you going to need to feed a lot of rotifers, plankton supplements to keep those animal healthy. Don’t think you going to find to many guys with experience with those cool water corals bellow 10m.
Two Oceans Aquarium and Ushaka have deepish cool water display with the corals you refer to- so pretty sure it can be done.

The deep reefs on our cooler east coast are spectacular so I can easily see why somebody would want to give it a go.

Keep us posted with pictures!
 

Riekert Botha

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Just to clarify, are you referring to actual plants like seaweed or do you mean corals?
Cold water do not really have corals, so mainly plants - a zillion different kinds
 

Riekert Botha

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Keep us posted with pictures!
Adrian, thanks for this reply. I'll surely post pics! I'm quite excited.

Thanks for the advice on the feeding. That's valuable info. So, a chiller is a must and probably a wave maker of some sorts to provide a mild current. Apart from a protein skimmer in the sump what else would you recommend?
 

Riekert Botha

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The issue would be the heat they transfer into the water, that would force you to use a chiller. Or bigger chiller.

As a side note, although off topic. Run external pumps wherever you can.
Riaan, thanks a lot! This helps. I plan to recreate a rock environment in 50% of the tank (with a swim through) and a sandbed environment the other 50%. The tank is 2meters thus providing adequate space for both.
 

Riekert Botha

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You mean seaweed? The biggest issue keeping seaweed isnt lighting, but nutrients.
What's your advice? How do I ensure the correct levels are present?
 

459b

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Keeping seaweed is hard mainly because what the seaweed needs, so does the nuisance algae. You'll need heavy feeding and massive filtration to succeed. Might be easier to keep some of the local NPS soft corals like Alcyonium and anemones.
 

RiaanP

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you get awesome cold water rock anemones. All different colors. Biggest problem is to be able to get them without hurting them. But they will require light.
 

Adrian B

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Riekert assume you talking about keeping the kind of things in the images attached? Those are sponges, tunicates, corals etc., very few seaweeds.

Philips Reef PE.jpg


Scuba-Diving-Port-Elizabeth 2.jpg
 

RiaanP

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yes, those rock anemones would require lights.
 

RiaanP

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nope, sorry, led light strips are weak. Check the total wattage on a strip.
 

Adrian B

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Sure Rian is correct - you will still need decent light plus lots of plankton supplements.

Reason the cooler east coast reefs have such prolific growth is due to the regular upwelling of nutrients during periods of East wind. If you live at the coast you will know the East wind pumps all the time.

And as somebody else mentioned the challenge you going to have with that is controlling the unwanted algae species that will thrive on those nutrients.

Would invest in a good skimmer with that system.
 

Riekert Botha

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Sure Rian is correct - you will still need decent light plus lots of plankton supplements.
And as somebody else mentioned the challenge you going to have with that is controlling the unwanted algae species that will thrive on those nutrients.
Adrian, hi! Here the original questions pops up again - and pardon me for asking it again. If a marine tank can flourish (or maybe it is just survive) without artificial lighting and no additional nutrients, why would I need the "heavy stuff"? I am not against lighting, but just htinking: If I do not need R6000.00 worth of lighting I will not use it. Here are some pics of the tank in question (I also admit it is not overflowing with corals and plantlife)...

img-20160127-wa0009.jpg
 

RiaanP

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The smaller anemones are flower pot anemones most likely. Can find them even on the underside of rocks during low tide being exposed but retracted. They are nmot that much light demanding.

You do not need expensive LED units. Old style T5 will still do the job. And depending on tank width, even a dual with proper reflectors would be great. Less heat into the water.
 

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