A Few CFL-related Questions - The Planted Tank Forum
LinkBack Thread Tools Display Modes
post #1 of 7 (permalink) Old 05-18-2013, 06:31 AM Thread Starter
Wannabe Guru
Django's Avatar
Join Date: Jun 2012
Location: MA
Posts: 1,002
A Few CFL-related Questions


I have a 10g planted tank with 2 14w CFLs mounted in "brooder" type dome reflectors vertically oriented. I will be getting rid of half the gravel leaving 1-1/2" substrate depth. The photoperiod is 8 hours right now. I have a Cyanobacteria bloom going, probably caused by too much dissolved organic compounds from not vacuuming the gravel. I got around half the gravel during a water change this week and I will cover the rest this week-end.

Question 1: I prefer a photoperiod of 10 hours. Is there anything "better" about 10 hours than current 8 hours, or is it just that when I started, someone told me to start out with 10 hours? I acknowledge that it is not a good time to increase the photoperiod with Cyano in the tank. But one day the Cyano will be gone, and it would be good to hear what I should do then and how to do it. The Cyano doesn't seem to have as much punch to it right now, since I vacc'd the gravel.

Question 2: Is 2 14w CFLs enough, not enough, or just right for my 10g?

Thanks for any help on this.
Django is offline  
Sponsored Links
post #2 of 7 (permalink) Old 05-18-2013, 02:23 PM
Obsessed? Maybe
somewhatshocked's Avatar
Join Date: Aug 2011
Location: Louisville, KY
Posts: 12,165
If the tank is planted, why are you vacuuming? Or are you just removing mulm from the surface of your substrate? Either way, unless it's really unsightly, it's good for your plants.

Two 14w CFLs is actually a lot of light for your tank. Are you using CO2 and dosing ferts?

If you want a longer photoperiod, you can go the low light route, use smaller bulbs or break your photoperiod up into two segments a few hours apart. Some members like to have their lights on in the morning, off a bit during the day and on again in the evening when they're home to enjoy their tank.
somewhatshocked is offline  
post #3 of 7 (permalink) Old 05-18-2013, 03:22 PM
Planted Tank Guru
acitydweller's Avatar
Join Date: Dec 2011
Location: New York
Posts: 7,695
just to toss this for consideration, all my tanks run a 6 hour photo period. why? because i am not home most of the day and it serves to keep all my plants lush and healthy. Of course the quality of light and fert dosing must be considered but if you are dealing with algae, youre going to have to curb either light intensity, duration, purging the excess nutrients in the water column/substrate and likely several other factors to get the tank into a good place.

"I am Groot", the faithful protector
acitydweller is offline  
post #4 of 7 (permalink) Old 05-18-2013, 04:19 PM Thread Starter
Wannabe Guru
Django's Avatar
Join Date: Jun 2012
Location: MA
Posts: 1,002
I am vacuuming the gravel because there's too much gravel (3") and there's a lot of gunk at the bottom. I'm doing this because I think it is a source of dissolved organic compounds, the cause of the Cyanobacteria I have right now. I am also getting bubbles from the substrate, which indicates an anoxic condition. I am trying to siphon up some of the gravel too.

I am not using injected CO2. I just don't want to get into it. I will raise the lights or go to 2 x 10w if I really can't shake this Cyanobacteria.


My photoperiod is 8 hours. I hope sometime I can put it back to 10 hours like I used to have it - the plants were doing very well. Granted, they could have been running on internal resources.

Thank you both for your input.

MY TANK: Planted 10g; 2 x 10W CFL; Fluval U2 internal filter; MGOCPM/black sand cap
A Silent Cycled Tank
Django is offline  
post #5 of 7 (permalink) Old 05-18-2013, 04:24 PM
Obsessed? Maybe
somewhatshocked's Avatar
Join Date: Aug 2011
Location: Louisville, KY
Posts: 12,165
Since cyanobacteria isn't really algae, you can treat it with Maracyn-Two. That's worked well for me in the past and has never harmed even the most sensitive shrimp, fish or snail.
somewhatshocked is offline  
post #6 of 7 (permalink) Old 05-18-2013, 09:28 PM
Algae Grower
Join Date: Oct 2012
Location: New Orleans, LA
Posts: 125
I was getting lots of GSA, but not cyano and had to cut my photoperiod to 6 hours. I raised my lights 4 inches and put it back at 10 hours and haven't had any problems in a week.

jspk is offline  
post #7 of 7 (permalink) Old 05-18-2013, 09:56 PM Thread Starter
Wannabe Guru
Django's Avatar
Join Date: Jun 2012
Location: MA
Posts: 1,002
Both sound like very good suggestions - thank you.
Django is offline  

Quick Reply

Register Now

In order to be able to post messages on the The Planted Tank Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

For the best viewing experience please update your browser to Google Chrome