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Help When do you start to crank up the light on a newly set up tank?

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Soo...my new tank has been going for about three weeks now. I do have a little bit of algae here and there, but nothing over the top (so far). Plants are doing well, nothing has melted yet, apart from some older leaves. As I have a cleaning crew in form of some snails (Ramshorn, Theodoxus and Bladdersnails) and a few shrimp in there I currently do like a 10% waterchange most days, to get rid of what the crew leaves behind plus removing a little bit of algae.

My tank does get some direct light at times (sunset), as it sits opposite a west facing window, and I noticed that when that happens the plants start to pearl like crazy. They do pearl before as well, but by no means as strongly.

The light is a Chihiros A II, and it is set to 70% currently, going for 7h and 1h ramp up/down time. So have a bit of room to turn it up. I think I am happy with the duration for now, but maybe twiddling with the intensity would be good. The question then is - do you wait for your tank to be (mostly) algae free before increasing light intensity, or do you simply go by "it's been two weeks, time to turn it up a notch"?

I was also thinking to maybe only increase the light intensity only for a few hours, around the time the plants pearl most strongly already.

What do the pros here say? :)
 
So a few things.

But first, the answer to your question is you put in the correct light intensity and duration as soon as you plant. The plants don't 'grow' into a higher light intensity, they need that intensity right away and then later on they might need to be trimmed if they are overshadowing their neighbors etc.

So why are you getting algae?

Well probably because of the direct sunlight but possibly also due to water changes/maintenance. If this is a tank with aquasoil type substrate, chances are you were supposed to be doing 50% water changes every day in the first week, every other in the second week, 3 times in week 3 and twice and week 4. And then thereafter once a week. If this is not an aquasoil type substrate tank, then you can skip those extra water changes and regular 50+% water change once a week is fine.

Regarding the sunlight. Get yourself a par meter or download the free photone app. For that one follow the directions on a diffuser and take a reading the same distance from your light as the light is from the substrate. That will tell you how much light your tank is getting. Now the next time the tank is getting direct sunlight, go ahead and measure how much sunlight the tank is getting. You will find that the amount is massive. A typical high light tank gets somewhere between 50 and 150 ppfd at substrate. Whereas the sun through a window will produce about 1600 ppfd. Depending on how low on the horizon the sun is when hitting your tank that might only be a few hundred ppfd, but still, that's a LOT more than what we typically want.

Regarding duration... it might be fine, it might be inadequate. Its really hard to tell with 2 hours of your 8 hour photo-period being something less then what you actually want the plants to be getting. I personally don't do long ramp up and down periods for this reason. 10 minutes or less ramp up/down is fine and frankly I typically prefer under a minute or none.

Hopefully that helps. Good luck!
 
Thank you for the input!

I forgot to add that I do not use soil but inert substrate, and I've added some ferts in between to make up for the water changes. Also the ramp up and down is 30 mins each, so 1h in total - sorry, I didn't write that very clearly I guess. I'd like to keep that for the animals mainly, especially since the light turns off late at night. Though the ramp up could easily be shorter I guess, since the room is bright anyhow at that time.

The algae started growing well before I started the small water changes, I am simply assuming that is due to the tank being new. I did do about 5 weeks of dark start though, mainly to get biofilm growing before the algae can get in, and to have food available for the inhabitants. Having the tank cycled is a nice bonus, too. Most of the algae I can see are on the plants, apart from some GDA on the glass and foreground substrate (which is certainly due to the extra light).

I do have the photon app already, but measuring it won't tell me much I don't know already. I do pull down the window blinds most days in the afternoon to block the sun, but some amount of daylight will hit the tank no matter what.

So do I get you right that there shouldn't be any algae at all at this stage? From what I read having some in a tank this new is to be expected - my question is not really how to get rid of them right now, but more if I should try to give my plants more light now or rather wait until the algae recede.
 
The answer depends on what your wishes and goals are.
Why do you think you would need more light ? if your thought is that the growth is inadequate and you would like more faster growth more intense color then yes giving more light would be helpful. In order to prevent adaptative stress (i.e the plants reprogramming to accomadate the higher light), it would be advisable to keep the conditions stable which would make one argue that going high on the light at the beginning would make most sense. Dennis Wong's posts and tanks all talk about this.

That said, practically you already have sunlight issues, some algae (we don't know what type of algae, brownish diatom phase will go away on its own) are common in this phase but if you are already dealing with hair algae I would anticipate increase in your light would cause this to bloom more.

If this was my tank, i would ensure that my tanks are stable for 3 months or so and then if i am still not happy with the growth then slowly ramp up the light over many weeks (adjusting other parameters such as nutrition and co2 accordinly)

Sunlight is an issue, my tank gets lot of direct morning sunlight. In Fall and winter this is not a major issue but in spring and summer i am anticipating more algae issues and i have already started having some more algae.

Last but not the least, do you use Co2? this might be a more meaningful way of increasing growth than increasing light.
 
I'd like to keep that for the animals mainly

Fish and shrimps definitely appreciate ramp up and ramp down 💯💯

do I get you right that there shouldn't be any algae at all at this stage

Some algae at 3 weeks is totally normal 👌 your tank is definitely still just starting up.


It can be hard to wait 😅 but giving your take another month or two to settle in at this light level is fine. If you want to raise the light you can, I would do it a little at a time, watch it for a week or two and see what happens.

There's definitely no downside to giving your plants plenty of time to root in and get used to the CO2 levels and fertilizer levels you are using.

Once it has been up and really robust for several months, the sunlight should be less of an issue. Lots of tanks get direct sunlight without algae issues, if they are otherwise stable and full of healthy growing plants.
 

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