Aquatic Plant Forum banner

Too many lighting variables- sun, tinted windows, T5s & compacts

1549 Views 6 Replies 5 Participants Last post by  Kosh42|EFG
I've a 33 gal (approx) tank perpendicular to north-west facing double balcony doors, therefore lots of afternoon sun although it's winter so days are short.

These doors have some kind of coating on them that I presume is anti-glare or heat reflective?

1) Will this coating adversely affect the quality of light my NPT receives?

My confusion lies in figuring out how much artificial light to put on a timer to supplement the sunshine. I have two lamps as choices:
-a T5 with 3 x 21w tubes (one blue- is this actinic and so for corals?!) giving me nearly 2 wpg I believe
or
- a 2 x 18w CF lamp = roughly 1wpg?

or of course put both on the tank = 3watts per gal

...but I've read that compact fluorescent bulbs are more powerful than wattage suggests

ouch my head is starting to hurt again ;-)

2) Is 3wpg too much considering sunny aspect/ tinted windows or just have 2wpg with the T5s?

3) How long should they be on for in these conditions as I know its 8 - 10 hrs but where does natural light factor in?

and

4) How do forum members enjoy their NPT on long winter nights as I hardly get to see mine in actual daylight until the weekends due to work?
See less See more
1 - 7 of 7 Posts
I don't know what the coating is on your doors but I'd guess it would somewhat reduce the light reaching your tank. You'll have to observe how the plants react, but I think you should still get enough light to be useful in keeping them healthy.

The blue light in the T5 fixture is actinic and not useful to plants so you'd need to change it out for a bulb that has a temperature between 6500K and 10,000K. I'd start with using the T5 fixture (with three plant appropriate bulbs) and see how that works. You can always add the other light if you need it at a later time when the plants are established and might need a bit of a boost because they can use the light and are growing denser. Watch the plants, see how they grow - if they're stretching for the light/losing lower leaves/not coloring up properly/etc. add the other fixture. If everything is growing fine - don't mess with a good thing! :)

For my tank in front of a south-facing window I have my lights on a timer that turns on about 7am off at noon (the tank still gets indirect light from the window but the tank is much darker like it's under heavy cloud cover) back on around 5pm and off at 10pm. I angle the blinds in the window according to the season and weather, more open in dark cloudy weather and angled to block more light in sunny times. I like to see my tanks in both the morning and evening and that's why I've gone with the split photo period. If you're interested in seeing your tank only in the evening you can have your lights turn on later in the day and use a solid "on" time so you can see the tank when you're home.
See less See more
1) Will this coating adversely affect the quality of light my NPT receives?
Depends.
Is your window simply "low-E" or is it actually tinted? The "low-E" removes Ultraviolet and sometimes Infrared. Your plants don't need wavelength from either of these light spectrum.

In fact, some people that have a metal halide bulb place a piece of filtering glass between it and the tank so the little fishies don't get a sunburn. Although some people don't think its necessary to do this, I think its a nice gesture to the fish. After all, in nature they can find an area of their lake or stream that is deep enough to protect them from UV if its bothering them. In the tank they don't have this luxury. Well, I got off on a tangent didn't I???

Anyway, if it is in fact coated to remove some of the visible spectrum of light, you might be in for a problem if you wish to use it as a viable light source.
See less See more
@ cs_gardener
thank you for your informative response, the LFS replaced the actinic so I now have 3, 10 000 kelvin, bulbs. Your sneak peak into timing schedule is exactly the kind of straight forward advice a newbie like myself requires. Plus it's interesting to read how the pros do even the basic things!

@skuser
I'm sorry but I don't know what a 'low-E' is and therefore how to tell if it is one. The previous owners put on a film on the outside of the doors and it is quite reflective so I presume it was an attempt to keep the unit cool as we get a lot of sun in summer - but it's not that effective because we had to install blinds as well to combat the glare.

'Fishies getting sunburn', never thought of it that way- how refreshing:) I have to be mindful of bright light as I have two clown loaches that need their hidie holes- either that or I get them caps, sunnies and some suncream!:)

Thank you
See less See more
I'd rethink the 8-10 hr photoperiod. Its not long enough. The recommended photoperiod (daylength) for aquatic plants is 12-14 hr. Its especially critical for keeping floating plants. If you want to see your plants on winter nights, you can split up the photoperiod like cs-gardener has done. In my opinion, this is a really smart move.
'Fishies getting sunburn', never thought of it that way- how refreshing:)
Haha.
Yes, that was one of my more clever moments for the day.
Anyway, you shouldn't have to worry about it because normal glass filters out most of the bad stuff when it comes to window light. The only problem with bulb light is with the metal halides, not the fluros. You, or should I say your fishes, should be alright.
I'd rethink the 8-10 hr photoperiod. Its not long enough. The recommended photoperiod (daylength) for aquatic plants is 12-14 hr. Its especially critical for keeping floating plants. If you want to see your plants on winter nights, you can split up the photoperiod like cs-gardener has done. In my opinion, this is a really smart move.
That's good to know, as my tank gets sunlight for about an hour in the mornings and I was afraid I'd have to have the T5's on at the same time and turn them off just as I get in from work :( I will rethink so they are on 6am to midday, then 4pm to 11pm so that I get 13 hours in total, mostly when I can see it :)
1 - 7 of 7 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top