Algae/Light Question

[Hamsnacks]

Not too long ago I upgraded from a 60 Gallon to a 120.
Went from 4 lights to 6 Lights, running 8 Hours a day.
Liquid Fertilizer twice a week, with tabs in the sand as well.
Also Running CO2.

In my 60 Gallon, there was no Algae at all, the tank is heavily planted, have some nerite snails, Algae Eaters as well. However lately I've noticed my glass has some green spots on it and has gotten worse.
All my plants are growing well.

Should reducing the light to 7 hours a day do the job or should I drop it too 6 hours?

Also in regards to the light, would it be alright breaking up the time, for example instead of 1pm to 9pm, could I go Lights on from Noon to 3pm, then lights off and then on again from 5pm to 9pm? Or would that kinda confuse/mess up the fish and plants?

Thanks

 

[Colin_T]

Leave the current lighting times alone and wipe the green spots off the glass.

You can split the light into 2 sessions if you like or just turn them on later in the day, eg: 12 noon to 9pm. Then the lights will be on when you are at home.

 

[Byron]

Problem algae is due solely to an imbalance of light/nutrients. Algae is natural in any aquarium because light and nutrients are always present; in planted tanks, the goal is to have this balanced so algae is present but not problematic.

As Colin said, cleaning off the glass is or should be part of the regular weekly water change. I use a sponge scraper on all my tanks even though I do not see any algae; if I miss a week or two, inevitably I will see it appear. The biofilm that forms on all surfaces under water will host algae so keeping this in check on the front glass is necessary.

The new lighting may be stronger than formerly, and this could upset the balance that seems to have previously existed. Reducing the photoperiod can help, provided the intensity is within the "balance" range for the CO2 and other nutrients (which involves fish load and feeding as well as plant additives). My own tanks work with eight hours daily, one tank only seven, and algae is kept in check. Each tank can be different biologically, so you need to find that balance.

The tank lighting should only be on for a continuous period each 24 hours. This is critical for fish, as it governs their circadian rhythm. The "siesta" approach to planted tanks involving a period of say 4 hours lighting, 3 hours off, then another 3-4 hours was devised because of CO2 levels. In low-tech or natural planted tanks with no diffused CO2 being added, the natural CO2 that builds up during darkness can bee exhausted after a few hours, depending upon the plant load and light intensity. Providing a period of no lighting allows the CO2 to partially rebuild. This should not be necessary in high-tech systems with CO2 being added, as you can monitor the CO2 along with the other nutrients and lighting.

Fish are extremely sensitive to light; not only through the eyes, but every cell on the fish. I can go into detail if asked, but in summary the breaking up of bright lighting has a serious detrimental impact on fish, and is not advisable.