lighting upgrade: watts/gal question (and other various questions)

[CrohnieBoy]

Hi all.

I want to start keeping live plants in my tank. I need to upgrade the lighting. Iwas wondering ow many watts/gallon I should have.

The basic specs:
20 gallon high
3 inches small rock
1 15 watt fresh/salt water bulb
1 power filter
hang on glass heater 2 78 degrees
4 white clouds currently, should be getting a pleco tonight
My Nitrites, Ammonia and Nitrates are 0
My pH is 7.4
my GH is 4 degrees



I am thinking about one of the 3 following lighting combos:
1.) one 36 watt PC and one 55 watt PC (4.55 watts/gal)
2.) two 36 watt PC's (3.6 watts/gal)
3.) two 55 watt PC's (5.5 watts/gal)


Also, any suggestions on CHEAP CO2 solutions (that won't accidentally explode or kill the fish.) I have heard that Flourish Excel would be a good thing to use if not supplimenting the CO2.

Any and all help would be appreciated. I am currently reading as many other posts as possible to find these answers.

'Tank' you all for reading this.

 

[superjohnny]

That's a lot of light man. General rule-of-thumb for light is 2w/gallon. Maybe start with 1 36w PC until your tank gets stable and used to live plants.

That's what I'm doing at least... DIY CO2 should be sufficient as well for a 20g tank.

 

[fishaddict]

Fluorish Excel and others

I actually have a little something to say about the flourish products. Actually my lfs did. A man there said to use the tablets that you stick under the gravel there instead of the liquid. Supposedly the liquid becomes available to all different kinds af algae while the tablets are more available to the plants. Im not sure if thats right but thats what he said and so im going to see if i can get the same results with the little tablets.

Ill let everyone know what happens in about a month when everything gets settled in.

 

[RTR]

Beyond 3W/gal, IMHO & IME, you will need pressurized CO2, or you will have problems controlling the tank.

I use the Flourish line - Flourish Liquid, Flourish Iron, Flourish Nitrogen, Flourish Excel (on tanks between 2.5 and 3.0 W/gal)), and Flourish tabs. The LFS person was confused or misunderstood on the liquid vs tablet forms - strongly rooted plants (swords, crypts, etc.) may take nutrients from the substrate freely; many stem plants seem to need water column traces and other nutrients. Many planted tank folk do all the nutrients in the water column without problems.

 

[slipknottin]

What are the dimensions of your tank?

20x10x24 or 24x12x16


watts per gallon is a fairly useless way to measure light avaliable to plants

 

[skeletalmachine]

I have 2.5 watts of light over an 18" deep 55 gal tank and so far there hasn't been any plant that won't grow even with no co2. In fact, some plants grow a little too fast for me to keep up. Perhaps you should think about what kind of plants you want to grow and if you really need so much lighting.

 

[CrohnieBoy]

REPLY

Thank you all for your input.

slipknottin : the dimensions of the tank are 24x12x16

The reason I had such high wattage choices is that a friend with a reef tank was helping me. I now know that reefs take large amounts of light where it seems that you all agree that around 2 watts per gallon is good for freshwater.

The tank currently has some micro sword in it that isn't doing great. The LFS that I bought it from said it would be fine in low light (I currently have .75 watts/gal) Any success stories on this plant?

Last night I got some hornwort and Anacharis from a different LFS. They said these will do well in low light also. Any success stories on these also?

I also added a small Pleco to help the plants win the battle against the algae.

 

[RTR]

Microsword is a high-light CO2 supplement plant IME.

 

[djlen]

Sounds like you're getting some incorrect information from your LFS. Micro swords are definitely not a low light plant. However you can grow them successfully under 2-2.5 watts per gallon, and having already gone nuts with lighting and suffered all the consequences, I need to tell you that it might be better for you to start with NO MORE than 2 watts per gallon. Over-lighting your tank can/will cause all kinds of problems. Until you learn about the plants your want to plant and their needs, nutrient-wise, start slow with two watts per gal. You can always add lighting if you want or need it.
Len

 

[Matak]

Slip: Maybe it is time to discard the old W/Gal formula. How about something like this: lumens/inch² as a function of plant depth? A chart, perhaps? Whatever rule of thumb is used, it should be simple, yet effective.