Algae

Hi, I have a green stringy/slimy algae growing in my tank.. I havnt been able to get rid of it I don't want algae eaters as they flatten the scrapping in my tank.. I have just put my lights from 12/12 to 18/6 to give less light.. What else can I do to get rid of the algae? It's a tropical tank set at 24 digress celsius. Thanks

Algae for the most part extract nitrates and phosphates and use light to grow - lower these and the problem should be contained. Algae eaters as you know are a serious consideration if you wish to consider? I for one never had a problem with some algae growing in my tanks as long as it was not over-run by it so this can be considered as well. I think it gives the tank a natural look in moderation - depends on ones taste in aquarium aesthetics.

*BTW-sounds like common green hair algae. Algae problems are the best way to teach us to keep our water parameters in check .

Lower light is step one, so you are good there. Be sure to also manually remove as much as you can as well. An old toothbrush works well.

Do you have any plants in the tank? Live plants will help out compete the algae for nutrients.

Last line of defense would be some spot treatments with SeachemExcel or hydrogen peroxide. I prefer to use Excel as it is a liquid CO2 substitute that benefits the plants as well. Load up your daily dose into a syringe, turn off all your filters and air pumps to make the water still. Then squirt slowly onto problem spots. Let sit for 15-20 minutes then turn everything back on. Repeat this every day until you get all the problem spots. Same can be done with Hydrogen peroxide using a dosage of about 2-3mil per 10 gallons.

@ Dolfan and others. I never heard of this method so cant speak on the pros/cons but doesn't it seem like a quick fix that could backfire easily and teach others that quick fixes are wise? Like/said I'm not at all familiar with this .

1971roadrunner - As I stated it is more of a last line of defense. I suggest using it just to help remove the algae, once you get all the algae gone, then you can focus on keeping your parameters where they need to be so it doesn't come back. But if you have any algae in your tank, it is hard to adjust your parameters, light settings, water changes etc, to a point that will kill off the existing algae. That is why I suggest manually removing as much as possible with your hand or toothbrush. Then trying to use plants and good maintenance to keep parameters check. Lower lighting levels. Then using the Seachem Excel as a spot treatment can help finish it off if still having problems.

Also a common misconception with algae is that it is caused by excessive nutrients in the water. This is not true. Tom Barr (a planted tank guru, well known in the industry, pioneered the Estimative Index fertilization method) has repeatedly studied, researched, and stated that excessive nutrients will not produce algae. Algae is primarily caused by excessive light and low CO2 levels. A balance has to be met between light, CO2, and lastly nutrient levels. The concept of excessive nutrients not contributing to algae is Tom Barr's EI fert method. It basically floods the tank with way more nutrients than the plants can ever need, so there is no chance they run out. Then you use light and CO2 to control the growth and algae issues.

Where plants help is by using up the nutrients, producing CO2 at night, and also through chemical alleopathy (not sure on spelling). Many plants emit certain chemicals that inhibit certain algae and some plants to grow near them, as a way to better survival in the wild.

As to your point 1971roadrunner, I totally agree, quick fixes are never the best solution. You have to treat the root cause (which is probably excessive light and low CO2). Then once you get the algae eradicated you can keep it gone for good. Excel helps in that it on 1 hand introduces a chemical that plants can use as a CO2 substitute but on the other hand, that same chemical is an algaecide. So it is like a 1,2 punch on algae.

Thank you Dolfan , lots of truth to what you say. I of course agree with physically/manually removing algae as one of the first steps to controlling it but the knowledge/consideration of the CO2 involvement never really played a role in me keeping it at bay. Of course there are different ways in which to do this and the angle you present will, I suppose, help me if I ever become very interested in more advanced FW plant keeping. It was interesting of you to bring up allelopathy 'cause when I was researching SW algae for my soon to be algae refugium (now in use on my SW) the discussion came up quite a bit in determining which algae is best to use for filtering purposes. ttyl