[banderbe]

Curious to know what people think...

Given that all your other plant nutrients (including CO2) are available to your plants in adequate (or more than adequate) amounts for your level of lighting, what lighting changes will have a positive impact on the reduction of algae?

Assume that you have let's say 3-4wpg.

If healthy thriving plants are the true enemy of algae, then assuming your ferts are in order, it stands to reason that MORE light is a good way to stop algae.

 

[banderbe]

Most of the answers in the poll are possible, there is no correct single answer.

If the other elements are non limiting, a reduction in light intensity will add a more robust anti algae environment than higher intensity. It will slow growth, allow better plant health and a more stable system. Time of lighting can play a role going longer/shorter. Burst works well and allows less to be used for the remainder of the light cycle. I would say overall though at 10 hour photoperoiod, less intensity is the best option if algae is the only factor but there are other possible answers.

Still, way too many folks have way too much light as a rule.
Plants do not need that much and algae does do better as higher and higher light intensities are present.

Regards,
Tom Barr

So what IS "too much light" ?

I have 2.25 WPG and a mid-day 3 hour period of 4.5 WPG, and I am going to expand the mid-day period until eventually I have 4.5 WPG for the full 10 hours of my photoperiod.

 

[banderbe]

Every single time I see "experts" talking about combating algae, they *always* talk about nutrients, CO2, healthy plants, etc.

It seems to me that if you are having to back off your lighting, install UV sterilizers, etc., then you are fighting symptoms rather than the cause, which is an imbalance in your tank.

I could be wrong. I'm a noob, but this is what I have gathered after hours upon hours of reading people like Tom Barr, Roger Miller, old papers like the Sears-Conlin paper, etc. People may disagree about the nature of the nutrient imbalances, or how to go about correcting them, but I haven't seen anyone suggest that lighting is the problem.

As a temporary corrective measure, lighting could be eliminated or reduced but that's not a good solution and not a way to have a vibrant planted tank. Or so I have read.

 

[banderbe]

Water change, water change, water change.
With that amount of light you need to do a 50% water change at least every other day. Over time this will reduce the algae in your tank.

I have read some experts say water changes make an existing algae problem *worse* but maybe that's only for non-CO2 tanks... can't remember..