# Starting a Planted Tank



## geonut (Jun 24, 2012)

Most advice I've read about starting a new planted aquarium says to use lots of fast growing plants.

These articles also say to use low-medium lighting.

I thought fast growing plants needed high lighting ?


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## Professor Monkey (Jan 8, 2015)

Keep reading  There's lots of information and advice out there and it can be a daunting task to get to the level of understanding that you desire.

Fast growing plants will help absorb the various forms of nitrogenous wastes and excess minerals that algae thrive on. 

All plants require a certain minimum amount of light in order to produce enough food to survive. "Low" light species are ones that CAN survive with minimal light. "High" light species require more light to survive, but they can typically live and grow in "medium" lighting - however, to get the best colouration, bushiness, form, growth rate, etc they require much more light than other species.

Low light species will have better growth, colour, etc if they have more light than the bare minimum they require to just survive (ie. a low light plant will grow and look better in medium lighting). We usually match species to the amount of lighting that is being supplied to the tank in order to create a balance between the amount of light, CO2, and nutrients. When there is an excess or deficiency in one of these parameters you will get algae blooms and/or impaired plant growth.
A tank full of crypts should be matched with low to medium lighting since they are slow growing and can only make use of a limited amount of light - high lighting would be beyond the limit of the crypts' ability to absorb and utilize light, and the excess light would be available for algae to use.

It's important to remember that light is the "driving" parameter in this balancing act. The amount of light will determine how much carbon and other nutrients the plants will need to acquire in order to grow properly. If the plants are absorbing lots of light, they also need to absorb sufficient nutrients to build new tissue (grow) and make use of all of the energy they have acquired. A lack of nutrients will give impaired growth and result in a nutrient deficiency which can also be thought of as an excess of light. Likewise, if there is too little light, the plants won't have the energy need to make use of the nutrients for growth, and then those free-floating nutrients can be used by algae instead.

Plants are superior at acquiring and storing nutrients relative to algae. A balanced tank with minimal algae is one where the plants are absorbing most of the available light and most of the available nutrients so that there is nothing left for the algae to use. Since under natural conditions carbon is the limiting nutrient there are enormous advantages to adding CO2 - it will improve growth under all lighting conditions and is essential for high lighting.

Now, more to your question... There are some species like hygrophila polysperma which can survive in relatively low light, but are able to use as much light as is available for rapid growth (so long as there is enough CO2 and nutrients). My tank has medium lighting and the hygro grows so fast (even without CO2) that I need to trim it AT LEAST every 3 weeks.


To establish your tank you will need lots of leaves (biomass) to absorb the light and nutrients so that they are unavailable for algae to use. It's therefore important to fill the tank with lots of plant biomass. Over time, because your tank will have lots of plant biomass and the plants are easily out competing the algae, you can switch to slow growing plants which don't require as much maintenance - adjustments to lighting and nutrient dosing may be required if you change out a lot of the plants.

It's very likely that you will get some algae growth in the first few weeks. Remove what you can and give the plants time to grow and out compete the algae. Once the plants are established and growing nicely nearly all of the algae should go away on its own.


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## solarz (Aug 31, 2010)

geonut said:


> Most advice I've read about starting a new planted aquarium says to use lots of fast growing plants.
> 
> These articles also say to use low-medium lighting.
> 
> I thought fast growing plants needed high lighting ?


Nope, not always. The problem with high lighting is that algae also grows faster. If algae ends up choking your plants, then your plants obviously won't grow very fast. 

Unless you go CO2, you'll want to keep your light at the medium level, and use species that both grow fast and don't need high light. Fortunately, those species are pretty common: hygro, vals, hornwort, even duckweed and java moss.


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## geonut (Jun 24, 2012)

*Question*

Thank you for the awesome replies - very helpful.

I have a 50 gallon short tank which I plan to use as a planted tank.

I'd like to have mostly Crypts and Swords, with Eco-Complete and fertilizer tabs.

Jason at Pets and Ponds is recommending a Fluval T5 HO 2 lamp fixture (39 watts per lamp), saying that will be plenty of light for the tank.

This works out to less than 2 watts per gallon (which I assume is the equivalent of medium lighting).

I am thinking of purchasing the 4 lamp fixture, but all 4 lamps have to be on at once, so this would be overkill, I think. Although if in the future I decide to have higher light plants, then I wouldn't have to buy another fixture.

I plan to use CO2 at the lower level of 6-15 mg./l/ (pressurized).

Do you have any suggestions for which fixture would be the best for my planned set up, of the 2 mentioned above, or perhaps another brand which can function with either 2 or 4 lamps on a one time ?

Thanks in advance.

JD


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## Professor Monkey (Jan 8, 2015)

I have 2 regular T5 bulbs on a standard 55 gal and it gives plenty of light. Without CO2 I had some algae on startup, but none now that the plants are growing well the algae is gone.

2 T5 HO will probably put you on the higher end of medium light (if it's placed close to tank) and even with CO2 you may want a couple of faster growing plants at hand incase you need help controlling nutrients and algae at first.

4 bulbs would require LOTS of CO2, nutrient dosing, water changes, and trimming. You'll also probably need it situated higher above the tank.

Like you pointed out, some higher end fixtures can run either 2 or 4 bulbs and gradually ramp up or down the light output. If you have the money to buy one that fancy I'd recommend spending it on a bigger/better tank.
The 2 bulb T5 HO will allow you to grow nearly anything quite well.


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## geonut (Jun 24, 2012)

*Lighting*

Thank you so much - you have been most helpful.


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## solarz (Aug 31, 2010)

geonut said:


> Thank you for the awesome replies - very helpful.
> 
> I have a 50 gallon short tank which I plan to use as a planted tank.
> 
> ...


Crypts are slow growing, low-light plants, so if you want to keep crypts, stick with the 2-bulb fixture. It's enough for all but the most light demanding plants. You don't need CO2 to grow crypts and swords.


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