Direct sunlight

barbarossa4122

Guru Class Expert
Dec 29, 2009
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Hi,

My wife's 10g planted tank is very close to a window. Will it be OK to open the curtains and let the direct sunlight hit the tank for a few hrs a day ? The light for this tank is provided by a Catalina single bulb 24" fixture (6500K T5HO) raised 8" above the tank. Thank you.
 
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instantcrow

Prolific Poster
Jun 13, 2010
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Brooklyn
I've done it

For the last 10 months I've run an 11gallon tank with pressurized co2, 30-80umol PAR at substrate with EI. Have had no problems with direct sunlight lasting hours a day. Live in Brooklyn with southern window 5 feet from tank 8 stories up. Lots of sun especially in winter. I've had some green hair algae, but have been able to reduce it with decreased light, EI and water changes. I really think the slight algae would've been there regardless of sun.

I've measure the PAR of direct sunlight, and it wasn't that high. Maybe 10-15 umol measured from inside the tank.

Most others, and plenty of books, will tell you direct sunlight begets algae blooms. I've found otherwise.
 

Biollante

Lifetime Charter Member
Lifetime Member
Jun 21, 2009
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Surprise, AZ
Sun Light Upon My Tanks Makes Me Happy...

Hi,

I have a number of tanks that receive various amounts of sunlight throughout the year. :cool:

I really have not had too many problems, then again I don't get suicidal over a little algae.

Overheating is the biggest problem I have seen, but then this is “the valley of the sun.” :cool:

Also algae seems to be a transitional thing. :rolleyes:

Depending on viewing angles I have found a towel or “shade cloth” over the side towards the window can also be helpful. Light colored cloth seems to work best.

Just treat the sun as you would any light/heating source and account for it. :gw

Biollante
 

barbarossa4122

Guru Class Expert
Dec 29, 2009
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Biollante;58403 said:
Hi,

I have a number of tanks that receive various amounts of sunlight throughout the year. :cool:

I really have not had too many problems, then again I don't get suicidal over a little algae.

Overheating is the biggest problem I have seen, but then this is “the valley of the sun.” :cool:

Also algae seems to be a transitional thing. :rolleyes:

Depending on viewing angles I have found a towel or “shade cloth” over the side towards the window can also be helpful. Light colored cloth seems to work best.

Just treat the sun as you would any light/heating source and account for it. :gw

Biollante

Thanks Bio. I have a good cleaning crew(60 or more rcs) and so far no algae. My home is at a steady 73 to 75f 24/7 all year around but, I always watch the water temp. Of course I can always pull the curtains to avoid the sunlight but, I love the way the tank looks in the sunlight. Also I think is healthy for fish, rcs and plants to get some natural light.
 
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dbazuin

Guru Class Expert
Dec 30, 2009
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I agree the tank looks awesome with direct sunlight. And indeed it looks like the fish enjoy the sun. The going more to the area thats get the sun. The lighting comes from a other angle then the bulbs above the tank and therefore even the colors of the fish are nicer.
 

barbarossa4122

Guru Class Expert
Dec 29, 2009
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dbazuin;58495 said:
I agree the tank looks awesome with direct sunlight. And indeed it looks like the fish enjoy the sun. The going more to the area thats get the sun. The lighting comes from a other angle then the bulbs above the tank and therefore even the colors of the fish are nicer.

Yep. On a clear day the tank gets about 3 hrs of direct sunlight in the morning. It just looks great.
 

dbazuin

Guru Class Expert
Dec 30, 2009
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Yes sitting on the couch with a nice cup of tea watching the fish play in the sun is one the best moments of the day.
 

Gerryd

Plant Guru Team
Lifetime Member
Sep 23, 2007
5,623
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South Florida
I have found over the years that direct sunlight seems to induce flowering in many submersed Anubias....

No matter the direction or angle, if the sunlight hits it through the glass, it will flower soon after.

Not cause and effect, but noticeable.

I have found that EVERY fish looks better in sunlight this way...:)
 

barbarossa4122

Guru Class Expert
Dec 29, 2009
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Gerryd;58518 said:
I have found over the years that direct sunlight seems to induce flowering in many submersed Anubias....

No matter the direction or angle, if the sunlight hits it through the glass, it will flower soon after.

Not cause and effect, but noticeable.

I have found that EVERY fish looks better in sunlight this way...:)

I have some Anubias in that tank and I'll keep an eye on it. Yeah, the whole tank looks great in the sun.
 

barbarossa4122

Guru Class Expert
Dec 29, 2009
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Hi,

Well, the experiment is over. I got green algae on the glass were the sun light hit. I blocked the sun, algae gone.