Possible causes of my algae?

[Jambot]

I have a 20g long with 60 watts of light. Of the plants I have, there are 5 dwarf sags, 2 bunches of rotala indica, 2 bunches of ludwigia repens, and 2 newly planted pots of dwarf baby tears. Might not seem like much so far, but I've been waiting a few weeks to see how fast things will grow before I get any more. I have my lights on for 8 hours a day and I do weekly water changes of anywhere from 25 - 15% each time.

Concerning the fertilizers, after the water changes I put in half a capful of Flourish and a full capful of Flourish Excel, with another capful of Flourish Excel midway through the week.

For fish, I currently have 10 cardinal tetras, 4 cherry barbs, 3 julii corys, 1 swordtail, 1 dwarf gourami, and 3 shrimp.

Now for the algae, its green and was mostly just on the glass of my tank but now its starting to get on the leaves of my rotala indica and ludwigia repens. There's also a dark brown, almost black algae on my dwarf sags and I know isn't just the plant rotting because I can easily scrape it off with my nail.

My thought is that with the amount of ferts I add, coupled with the amount of light I have, I don't have enough plants to use everything up, so the algae's using it. Would you agree with me or am I way off?

Should I buy more plants, cut down on my ferts, get some otos until the plants grow in some more?

[sen5241b]

The thing is, different types of algae have different remedies therefor it would help greatly if you knew what kind of algae it is. There is an algae photo gallery with descriptions at about.com. In the mean time, I would reduce the lights to 6 hours a day for awhile.

[Dave66]

I have a 20g long with 60 watts of light. Of the plants I have, there are 5 dwarf sags, 2 bunches of rotala indica, 2 bunches of ludwigia repens, and 2 newly planted pots of dwarf baby tears. Might not seem like much so far, but I've been waiting a few weeks to see how fast things will grow before I get any more. I have my lights on for 8 hours a day and I do weekly water changes of anywhere from 25 - 15% each time.

Concerning the fertilizers, after the water changes I put in half a capful of Flourish and a full capful of Flourish Excel, with another capful of Flourish Excel midway through the week.

For fish, I currently have 10 cardinal tetras, 4 cherry barbs, 3 julii corys, 1 swordtail, 1 dwarf gourami, and 3 shrimp.

Now for the algae, its green and was mostly just on the glass of my tank but now its starting to get on the leaves of my rotala indica and ludwigia repens. There's also a dark brown, almost black algae on my dwarf sags and I know isn't just the plant rotting because I can easily scrape it off with my nail.

My thought is that with the amount of ferts I add, coupled with the amount of light I have, I don't have enough plants to use everything up, so the algae's using it. Would you agree with me or am I way off?

Should I buy more plants, cut down on my ferts, get some otos until the plants grow in some more?

The brown is diatoms; algae in a calcium-carbonate shell. You get 'em when there's a proliferation of silicates and the conditions are favorable for them to form. I know it doesn't sound right, but if you increase your lighting, they'll disappear.
Easiest way to prevent algae from forming is layout the plants in your planned layout, then just pack the tank with more of the same species. They'll use up all the algae feeding nutrients. After a month or so, when all the plants are settled in, remove the excess plants and you're set.
Use half-doses of those seachem things. Its the excess that the plants you have can't use that's feeding the excess algae. All newly set-up planteds battle algae, unless they start as I described.

Dave

[jbeining75]

Dave got me lol.... increase lighting and water changes to deplete the excess nutrients....... I was typing the oscar thing up lol .....