View Full Version : Question about how long to leave the tank lights on.

07-15-2010, 04:27 AM
Hey there. I have small tanks and when all is said and done the lights provide about 2.3 watts of light per gallon. So far I am doing well with the min swords, crypts, java moss balls, watermelon plant, and Rotala Rotundifolia.

They are all doing well and I am about to add some injectable CO2 (brewer's yeast and sugar with a DIY kit).

My concern is that algae is growing on the swords, the aquarium dividers (macrame canvass from a DIY project I did) and on some of the ornaments.

I leave my lights on for about twelve hours. And I leaving them on too long?

How long do you guys leave your lights on for your plants?

07-15-2010, 09:43 AM
I have three planted tanks and all of them get 12 straight hours of light a day. I have a little bit of algae here and there, but it's kept under control to a point where I like a little bit of it to complete the natural look; it's not overwhelming. Algae is pretty normal, especially at first. The trick is to find the right balance of light and nutrients which can take awhile; really you just have to play around with it and give it some time to figure out what works best.

A few things you can try to combat algae for now...

- Break up your light cycle in the middle. You can still keep it on for 12 hours, but try putting a 3 or 4 hour break inbetween. You could even shorten your light cycle a little bit down to maybe 10 total if you don't want a light on in the room for that long. Algae needs long periods of light to grow, whilst plants can almost immediately start photosynthesizing when the lights come back on.

- Invest in a couple otocinclus catfish. They do wonders for cleaning algae off of plants in smaller tanks, produce little bioload, don't take up much space in the water column that your fish use, and get along fine with most fish. Even dwarf puffers leave them alone when they pick on most other living things in their path. Three or four in a 10 gallon tank can be done no problem.

- Find a few bottom feeders that you like. While they don't really clean up the algae so much, they eat a lot of the extra stuff that winds up on the bottom of your tank which can be a major cause of algae. My 20 gallon has 5 cories, some ghost shrimp, some mystery snails, and a bristlenose pleco. I overfeed pretty much on purpose and it's spotless by the next morning, if not a couple hours after the lights go off. I never really have to worry about food sinking, and I try to do it half the time just to make sure everyone is getting their fair share that doesn't partake in the daily feeding frenzy on the algae wafer.

Hope I was of some assistance :22: , I'm sure you'll get some other good pieces of advice from some other members too.

07-15-2010, 10:32 AM
I run my lights for ten hours a day. Tryt different lighting legnths until you find the one that works for your tank.

07-15-2010, 10:49 AM
Thanks, Sun and Rich.

I didn't realize it but I have been leaving my tanks on for 14 hours. Yikes!

I reset the time to operate for 12 hours. I hope this will help.

Oh and I do have the otto fish and ghost shrimp. But I was getting black beard algae on a couple of sword plants and that was really annoying me.

I also had to stop using liquid fertilizer by API. I forget the name but I did not realize that it was creating insane amounts of algae. I had to take my tanks apart and bleach the plastic tanks because it was that really difficult kind of algae that would not come off.

Thanks! :goldfish: :fish:

Lady Hobbs
07-15-2010, 01:46 PM
You may be dosing too much fertilizer. I only use ferts in one tank that is jammed with plants. If your tank is only slightly planted or has slow growers, just a very small amount of fert is needed, if at all. If the plants can not use up what you are dosing, you end up with an imbalance of nutrients.

Before your algae becomes out of control, I would get a bottle of Excel and get that algae gone then with the less (or no) ferts and less lights, you may do better.

07-15-2010, 09:45 PM
Thanks, everyone. I have a lot of plants in my tank. It is like a jungle in all four of my tanks. My bettas and ghost shrimp seem to love it. thumbs2:

Can anyone recommend how much Excel Flourish I should use per gallon on a daily basis? I cannot seem to figure this out. Hope someone can help.

07-15-2010, 10:16 PM
On the bottle it says to use 1 cap full (5 ml) for every 10 gallons on the initial use or after water changes greater than 40% and then 5 ml for every 50 gallons on all other doses.

For my 10 gallon tank, I do a dose of 1 ml 3x a week (every M,W,F). I only do about 25% water changes on Wednesdays, so I just stick to 1 ml of excel, but I do it after the water change is done. For my 5.5 gallon betta tank I do the same thing except half the doses.

Basically, when you first start out, it's 5 ml for every 10 gallons and anything after is 1 ml for every 10 gallons. A little syringe will help you out a lot for smaller tanks. You can find them at most pharmacies if you don't have one.

Some people overdose or shoot concentrated excel onto problem algae spots, but this schedule will get you by for just your standard dosing. I'll normally try to shoot the excel wherever I see the most algae, but I don't know if it really does much with the filter running and moving the water around.

07-15-2010, 10:38 PM
Thanks, Sun. I did read the directions on the bottle but I was not sure how to work it out since my tanks are 6.6 gallons. Obviously if I had a 50 gallon tank I could follow the directions with ease.

So you only dose 3x a week? According to the bottle it says you can use it everyday or every other day. I wonder if I should use it every other day as I have "jungles" for tanks (very heavily planted tanks).

07-15-2010, 10:45 PM
I'd probably just go for something like 2/3, 3/5, 3/4 of a ml, anything in that range should be fine, just do whatever is easiest to measure for you. I'm sure even a whole ml wouldn't really cause any problems. I mainly did 3x a week to make things easier for myself, rather than having to remember which days I dosed or having to write it down or anything, I just know that every Monday, Wednesday, and Friday I dose the tanks.

This is what my 10 gallon tank looks like normally...
So, it's pretty heavily planted too, and the excel seems to work well in the amounts and times I'm dosing it. As far as I can tell, anyway, I have no control variable to compare it to really, but between the otos, fast-growers, and excel, I don't have any problem algae to speak of.

07-16-2010, 12:02 AM
Daaaaaaaaaaaang, Sun. Your planted aquarium is GORGEOUS.

That is a stunning tank.

07-16-2010, 12:55 AM
Ha, thanks. Took some learning and time to get it to this point. This was my first planted tank and I'm still looking to improve it. I'm still going to be tweaking a few things here and there yet, but most of what I've learned has been from this site. The possibilities are endless thumbs2: .

07-16-2010, 01:19 AM
Mind if I ask you questions about you tank?

What light bulb brand do you use and how many watts are you getting per gallon? I will need to replace the bulbs in my tank soon, so far I am using the ones that came with it. So far so good but not sure what brands people recommend. I will need the 18" long fluorescent bulbs.

How do you clean the gravel? I cannot vacuum my gravel since all the plants are sort of in the way.

In my 6.6 gallon tanks I keep just two bettas with a divider in the middle but after taking the tanks apart and cleaning everything thoroughly I see how much they poop after just 5 weeks. Oiy! :hmm3grin2orange:

07-16-2010, 01:32 AM
Mind if I ask you questions about you tank?

What light bulb brand do you use and how many watts are you getting per gallon? I will need to replace the bulbs in my tank soon, so far I am using the ones that came with it. So far so good but not sure what brands people recommend. I will need the 18" long fluorescent bulbs.

How do you clean the gravel? I cannot vacuum my gravel since all the plants are sort of in the way.

In my 6.6 gallon tanks I keep just two bettas with a divider in the middle but after taking the tanks apart and cleaning everything thoroughly I see how much they poop after just 5 weeks. Oiy! :hmm3grin2orange:

07-16-2010, 01:52 AM
No problem...

Believe it or not, I'm using a real cheap-o set up here for this tank. Like I said earlier, it's a 10 gallon tank, so I got a simple hood at walmart (I think it was maybe $13) that can fit two screw-in type bulbs. They also have little fluorescent bulbs in their aquarium section (I think made by GE?) that are conveniently rated at 6700K, perfect for aquarium plants; they'll run you about $5 a piece. The kind I got are 10 watts each (giving me 2 watts per gallon), but I think I've seen on here there are also 15 watt versions walmart sells. I guess it depends on the size of the one near you. Total cost for the hood and lights was something like $25. One thing I do hate about the hood, though, is that the opening is so small, so you if you ever want to do anything in the tank besides feeding, you have to lift the whole thing off.

As far as cleaning the gravel, you really don't need to. In planted tanks, all the junk (in your case betta poo :lol:) you would normally try to clean up gets used by the plants. Lucky you, makes your job a lot easier; just another benefit of plants. Unless there are big sections of gravel that have no plants with roots going near it, you really shouldn't need to worry about gravel vacuuming, even then it's probably not really necessary unless your nitrates sky rocket. If the surface of the gravel starts to look nasty you can kind of stir up the water around it and let your filter catch it or let your gravel vac just touch the surface, but try not to go into the gravel itself. Most bottom feeders will take care of that nicely for you as well.

Since you have a 6.6 gallon tank with a 18" light, I'm guessing you have one of those petco bookshelf aquariums? I'm not sure what the light fixture for this tank can hold, but you'll want to max out the wattage as much as the fixture will allow with a bulb somewhere around 6700K. The brand of light really isn't so important as much as the Kelvin rating and wattage, assuming they're not so poorly made they burn out before they're done being useful, which is about a year or less anyway.

Anyway, 1.5-2 watts per gallon is a pretty good start, especially for long short tanks like that which don't need quite as much penetration power to get light to the bottom. Just to make sure before I give you any other advice, can you tell me how many watts your light fixture will allow and what "T" type of bulb the fixture will hold? If it is one of those bookshelf aquariums, I believe it's a T8 bulb.

07-16-2010, 03:41 AM
Hey there, it is the bookshelf aquarium. At this point all I know about the bulbs is that they are 15 watts each. So this gives me 2.3 watts per gallon.

Wow, thanks for that amazing and thorough response.

I was told that bulbs need to be replaced every six months. So I plan on doing that.

I do not know what the T8 stands for. Is that the prongs that connect the bulb to the outlet source in the hood?

07-16-2010, 04:34 AM
Ok, well if you have 15 watts on the tank, you can probably grow a good amount of plants, but you'll want to replace it with a proper Kelvin rated bulb. They do sell T8 bulbs at petco that I believe are rated at 6500K, which should work just as well. The "T" rating on a bulb has to do with the diameter of the bulb. T5 is the next standard you'll find and actually produces more light, although it has a smaller diameter.

I did have one customer I was talking to a couple different times that had one of these bookshelf aquariums and I had shown him a 15 watt T8 bulb to replace the one in it. He was having some problems growing plants for quite some time, but I later found out he was using nitra-ban which was more than likely starving the plants of any nutrients his fish were producing for him since he wasn't dosing any other fertilizers either. I also later found out he had goldfish in that tank :rolleyes:.

That brings up another thought... you'll want to remove any carbon from your filter and stop using any additives like nitra ban that will remove nutrients from the tank.

Honestly, I'm not entirely sure how well the plants will grow with a T8 bulb, because the only similar situation I know of is the one guy that was removing nutrients. It does have a good amount of wattage behind it for the tank, and the tank is pretty shallow, which is a plus, so I think it'll be a lot of experimenting on your part to see what works. You should be able to get away with a fair amount of plants once you get the proper bulb in there I would think.

Bulbs should be replaced every 6 months to a year is normally what I hear. I shoot for around 8 months to just hit the middle of the road. The same goes for UV bulbs for reptiles.

07-16-2010, 07:11 AM
Thanks again for all that information. I am currently using the Aqueon hang on the back filters. I bought the ones for ten gallon tanks so that it would be more thorough than not enough. But if you are saying that I should remove the carbon then what do I use for filtration?

Are you saying that I should not use carbon at all? I am not sure what to do to help keep the water clean.

Mind explaining please? :11:

07-16-2010, 07:42 AM
No problem. Gotta pay forward all the info I learned on here somehow :lol:. I actually have the Aqueon 10 gal. HOB filter running on my 10 as well.

All I did to get the carbon out of the filter pad is I took a box cutter (any sharp blade will work) and cut a slit running across the top part of the filter floss/fabric/whatever you want to call it and banged out the activated carbon that comes with it over a trash can. If you're doing it to a filter that's already wet, you can do it in your water change bucket or just have some used tank water near by to keep it wet and save your beneficial bacteria. I cut mine on the back side so the flow of the water will keep the floss stuff pushed up against the filter rather than pushing it out towards the tank. I guess it wouldn't make much of a difference which side you cut, but that makes more sense to me given a choice.

I suppose at this point you could shove a small amount of filter media in there if you wanted to, but I never bother and have never seen any adverse effects in my nitrogen cycle. Basically, from the conclusions I've come to on it anyway, carbon is great for getting rid of some smells, discoloration (especially tannins), and medicines when you're done using them, but in most cases there's not really a need to use it. Just a way for the companies who put the stuff in there to get you to replace their fancy little cartridges every month.

I forget which thread I read this on, but I saw that carbon can actually absorb some of the nutrients your plants will want to use as well, so I always make sure I remove the carbon before putting in a new filter. The only time I ever put in a new filter pad is when giving it a good scrub down in used tank water still results in the water flowing up around and over it. I think I started up my 20 gal in November or so of last year and have only just replaced the filter pad in it for the second time yesterday: I think putting new substrate in there within the past month had a lot to do with clogging it up this time around too.

The main things that will be keeping your water "clean" are your beneficial bacteria that will reside in your filter mainly, your plants that will be sucking up all the other bad stuff, and your filter floss itself which mechanically removes any debris that comes through the filter. Carbon is not really a necessity in my opinion, nor is any chemical really. There are a good few threads on the forums that go pretty in depth into the ins and outs of activated carbon in the aquarium if you want to search for them. Everything I've just said is a pretty basic summary of how I've come to understand it.

Seems like most people on here believe in using as much mechanical and biological filtration as possible while skipping out on the chemical when it's not necessary. I like to think of my tank as a little more self-sustaining that way too, knowing it doesn't need to be dependent on chemicals to keep it clean.

Man, why do my posts always seem to end up being so long-winded :lol:.... bad habit of mine :11: .

07-16-2010, 04:57 PM
Wow, that was a great explanation. I really appreciate you taking the time to explain all of this for me. I guess if I have anymore questions I can always e-mail you but for now I have to jet. Thought I would sign on and check to see if you responded.

Thank you very much. thumbs2: thumbs2: thumbs2:

07-16-2010, 06:45 PM
No problem. Would love to see some pics of the tank once you got it all set up to your liking thumbs2: .