Lights On or OFF during cycle?


Good day Guys
At last i have all the equipment i need to start my 130G reef.
I would like to find out what would be the best.
I'm starting with a 2 inch Fuji sand bed and a truck load of base rock.
I am also busy seeding some base rock in my current 30G tank which i want to shift over
at some time.
What would be the best?
1, Lights on or off?
2, live rock from start or after major cycle?

Thanks in advance


I don't think it matters if the lights are on or off. I also started mine with the lights off and didn't have any problems.

As far as LR from the start or not, again I don't think it really matters. It might shorten the cycle some but I wouldn't think the time would be noticable.

Don't forget, pictures once you get it all together.


Thank you for the advise. This means i can start the tank in about 2 weeks when my Sand and salt arrives. I am only expecting my light mid January.
Should i add a piece of biological material to kick-start the cycle or not?

bang guy

1 - For me, it's on.

2 - I have had the best success with some live rock right away but doing water changes to keep ammonia below 0.5ppm, then add the rest of the rock (high quality) after that cycles and repeat (always keep ammonia below 0.5ppm).


Well-Known Member
Lights on.

if the tank clouds up the kill the lights until it clears.

the resume with less lighting and adjust to the max clear tank.


Ok after reading your question one more time let me say this. There are two parts to setting up a new tank:

Curing Live Rock
Cycling a tank

These can be done at the same time but that is your choice. I personally do them at the same time.

Curing live rock is the process of removing any dead organisms on the base rock while growing benefitial bacterial on the surface of the rock.
It is this bacterial which will start the tank cycling by converting the Ammonia (I throw in some fish food to start it) produced from fish waste into Nitrites and then into Nitrates. When you first state cycling a tank the ammonia with spike which will feed the bacteria which consumes the Ammoinia and then your nitrites with rise until the baterial is created which consumes the Nitrites and so on.

The one negative about running your light too much during this phase is the appearance of algea and the bacterial you are growing on the rock do no need light to grow but a good water flow will help.

Additionally, if you do water changes during your inital cycle this will do nothing but to lengthen the process. If you have nothing in your tank, the elevate ammoinia isn't going to hurt anything but help build up the good bacterial quicker. Mother nature will do it's thing to reduce Ammonia on her own. You will know when the cycle in complete when your Ammonia, Nitrites are zero and your Nitrates are below 15 ppm. This process should take about 4 weeks but can vary so water testing is the only way to know for sure. Then you can add fish SLOWLY so you don't start another cycle in your tank.

bang guy

In my experience very high ammonia levels extend cycle time and kill off a lot of the live rock infauna to the point where the rocks become phosphate sources for filament algae. From research it seems that high ammonia levels is toxic even to nitrifying bacteria. This is not a case where more is better.

As long as there is some amount of ammonia, water changes will not extend cycle time and you end up with greater biodiversity in the live rock.


Hi Thank you for the replies.
Would the bellow spcs be to to much? I have the option to go half the amount of bulbs?

ixture comes with 48x 10000K white 3 watts LEDs and 16x Actinic Blue 460nm 3 watts LEDs

30cm extra extend, fits to 120-150cm fish tank