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Does a dirted substrate allow for indirect sunlight?

1592 Views 9 Replies 4 Participants Last post by  Django
Hi. I am considering taking off my backing which keeps the indirect sunlight from my North-facing window out of my tank. It caused a big algae problem when I had gravel and Flourish Comprehensive and Root Tabs (I'm not completely sure I had those micros then) and I notice that my plants are doing better now. Hypothetically, it's because of the nutrients in the dirt.

So do you think that the CO2 will be enough with 12 hours of indirect sunlight on the tank? I guess I wouldn't be able to supplement that with the lights so much.

Thanks for the help.
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I keep most of my dirt tanks in windows, but there's plenty of floating and emersed plants in them... also some algae, but it doesn't take over or anything.
Perhaps people(I for one) don't undersatand what you mean by indirect.
It's loudy now but if direct sunlight were coming through my window I could see
it hitting the wall on the other side of the room. If my tank was in that light, it would cause algae if more than 20-30 minuits per day.
The rest of the room however is lit by indirect sunlight. That type has virtually no effect on tanks.
The window is about 6 feet from the tank. It faces North down an alley towards a 4-story building - only a square of blue sky can be seen.

I'll try to guage whether whatever light there is is directly hitting the tank.

Lost my text because I forgot to log in. Very frustrating. I have been thinking about the light issue for my tank and I don't think my tank can take a lot more light. I think maybe I can get away with lowering the lights an inch or two and exposing two inches of the back glass.

I have two 10W CFLs in aluminum dome reflectors and a 10g tank witht MGOCPM+sand substrate and moderately planted at this point. Things are looking alright although some of the plants could be growing faster, particularly on the substrate.
The non CO2 level of that type of light without getting algae problems is one of those shades and they usually have a 13W bulb. With the CO2(which I'll presume to be DIY)
may be OK/w 2 of them, but also could by why you got that algae problem.
Like there are a couple of house plants which can doc well inside without direct light
from the sun so I can't completely discredit it. But green water/GSA/Hair algae and
that type which looks real close to it but is more wiry than slimy...they pop up
easily with direct sunlight.
Most of the feedback I read on here suggest better ferts to get the plants growing better as the main remidy for algae. Another thing about algae is it usually takes
prolonged periods of light to grow.
IF your objective is to increase the plant growth, I'd work on learning more about ferts
first. Light does drive plant growth. But they need complete food to go/w the light.
We tend to look at people eating all sorts of stuff which doesn't always have good food value and not seeing them have issues...but these plants are continously growing and
when one nutrient runs out in the tank, the plant can't grow past that point.
I would suggest reading this and then see what you think.
I've heard that the type of sub you have can be short on one or two nutrients.
It has some of them but not as much as the plants(depending on which kind) need.
AND for example Anubias and Java Fern take nutrients from the water, not the sub.
And that sub doesn't have enough Potassium for Wisteria(possibly, perhaps likely).
But see what you think about the info on that link.
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Hi. I am considering taking off my backing which keeps the indirect sunlight from my North-facing window out of my tank.

Personally, I'd leave well enough alone. In real practice, sunlight levels are so variable from day to day and throughout the year as the earth moves around its axis that it makes achieving balance very difficult in an indoor tank.
Thank you both for the feedback. MGOCPM has an NPK ratio of 0.10-0.05-0.05, with 0.05% soluble potash (K2O). Is that enough? I even have Potassium that I figured out the dose for, and which has no overdose effects. I could even start adding a half-dose of Flourish Comprehensive for micros.

Anyway, I agree that too much light produces a condition of not enough fertilizer. I will read the thread that you mentioned. Any response to the above?

Thanks a lot for helping me with this little obstacle issue.
There's really no way to answer your question with any accuracy. Every tank is going to be different, due to different species and size/overall plant mass versus bioload, light, and innumerable other variables.

The best thing is to just learn to watch your plants. With a little trial and error and research, you'll quickly learn to spot the various growth patterns/discolorations/holes that are the symptoms of a nutrient deficiency.
Ok, I read the thread, got some good things out of it. And lauraleellbp, your point about reading the leaves is a good one.

Ferts: I am going to assume I have enough ferts in a dirt tank.
Light: I have a good deal of light without opening the back. I have almost no algae at this point. Opening up the back would make the photoperiod roughly 12 hours per day and longer later on.
CO2: This will be the limiting factor on growth. I may have to reduce the lights if I start getting a lot of algae. Photoperiod is currently 9 hours and seems to be ok. However, the CO2 level can not support the current light level, let alone a clear back.

Thanks again!
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