Fish Only Lighting

[Vicki]

What would the optimum number of hours be for lighting a Fish Only tank?

Vicki

 

[returnofsid]

The amount of hours you would like to be able to see your fish basically. Too much lighting and you run a chance at an excess of algae. Other than that, it's totally up to your viewing pleasure.

 

[Vicki]

I already have plenty of algae in this tank and would really like to cut back on the lighting, but don't want to take away from my fish any necessary lighting for them to be able to absorb what-ever-it-is they get from the lighting. (This is my ClownFish display/breeding setup.)

I guess I should have asked what the minimum amount of lighting would be for the health of the fish.

Vicki

 

[Krish]

Vicki, I think fish only need about 5 hours or so of light a day (if I remember correctly, but could be wrong) to process vitamin D which I think is what they use light for. I guess someone else will chime in to confirm though

 

[Scooterman]

I think like Krish said is right, I'd personally would go between 6 & 8 hours a day If you can, I don't think It would worsen your algae problems, maybe not help as much as total darkness but shouldn't make it worse because of that.

 

[Slag]

an idea to help with your algae problem is here http://www.reeffrontiers.com/forums/showpost.php?p=349051&postcount=132

 

[leebca]

A simple (yet unchanging) rule of Mother Nature is to take advantage of all nutrients. Algae covers a wide range of organisms. Many can live with little light. Others can, to some minor degree, adjust to lighting provided. The bottom line is this: Controlling the amount of light really doesn't do well for controlling algae.

If you have an algae problem (I don't even though I over stock and over feed by FOWLR marine systems), then you want to remove the nutrients the algae is living on. Most higher forms and many micro algae (that are TRUE algae) require phosphates, nitrates, organics, and micro elements (e.g., iron). Controlling these (or setting up a refugium to compete for these nutrients), rather than lighting is the way to go to control algae.

However, back to your original question. Fish live at all water depths in the reef. Some live so deep that light is very weak. They need very little light if they are being fed properly and properly nourished. So as previously mentioned, the length of lighting should be to suit your preference and enjoyment of the hobby (and to show off your accomplishments to visitors!).

 

[Vicki]

Thanks everyone for all your help.

This particular setup gets quite a bit of natural daylight as well as it's artificial lighting. Most of the algae grows on the viewing surfaces. Within a week's time of thoroughly cleaning all the algae off and removing everything that has accumulated in the tanks, the algae is back to the point you can hardly see the fish in the tanks closest to the natural daylight source.

My nitrates are low (usually less than 10ppm) for a heavily populated fish only system. I'll have to check the Iron and Phosphate levels as those aren't things I test for very often in this system. I don't want a refugium on this system as I've tried for the past year to remove all 'pods, worms and stars (they attack unattended Clownfish eggs).

Would adding some snails to this system help in keeping the nutrients and organics lower since I have very few 'pods, worms and stars?

Vicki

 

[dnjan]

You might not be able to get an iron test kit (at a reasonable price) with enough precision.

If you have lots of fish, you have lots of fishpoop. Sounds like you got rid of one set of fishpoop-processors (the pods, etc), so you need to find another way to get the fishpoop out more quickly. Lacking a sump (you did imply no sump with the no refugium comment, correct), you are forced to go with another method. Water changes, big and often, would probaby work.

 

[Vicki]

I found an 'old' Iron test kit and just finished running the test and it's showing 0 for Iron, both non-chelated and chelated.

Also just ran a Phosphate test and it's showing 0 Phosphates.

I do have a large sump for this system with aggressive protein skimming, UV unit, sulfur denitrifier as well as three filter socks which are changed about three times a week. I also run a kalkwasser stirrer with an auto top off.

Vicki

 

[dnjan]

What is the precision of the iron test kit (what was the lowest reading above zero?)?

You may still be having a problem with detritus in the main tank decomposing. Higher flow and no dead-spots plus filter socks (regularly changed) may do the trick.

 

[leebca]

If the algae are consuming these nutrients, I would expect the iron, phosphates, and nitrates to be low. Anything growing in the sump?

 

[Vicki]

If the algae are consuming these nutrients, I would expect the iron, phosphates, and nitrates to be low. Anything growing in the sump?

Awwww, a benefit of algae growth?

There isn't anything growing in the sump other than those spirorbis critters and a few Q-tip sponges. Zero algae in the sump.

Vicki

 

[leebca]

Actually, it is a benefit. That is why some people keep refugiums with macro algae. It robs these nutrients from the nuisance algae.

If the sponges are the type that are filter feeders and they are doing well, then I wouldn't be surprised if the marine water is nutrient rich.

 

[Krish]

I agree on the nutrient issue as the reason for excess algae growth and not necessairly the lighting as such. I think the light intesity will only determine which type of algae you will have grow in your system. Minimize the light and you will probably have a low light demanding algae grow...Use more intense lighting and possibly another type of algae will grow instead. Once there is excess nutrients in your system that aren't being dealt with via skimming, water changes etc, then some form of algae will grow