Green algae on Jura Rocks

[jeromecarlyoung]

Hello,
I have a problem with green algae only being on my Jura rocks.
I have a 10 gallon tank with 2 Otos and one Dwarf Puffer.
The water is changed up to 60% a week (two weekly changes of 30% each and the Ammonia is 0ppm).
The plants I have seem to be going brown round the edges and are cut back every 6 weeks.
The problem is that my Dwarf Puffer only used to like eating Pond snails but suddenly changed to eat my Malaysian Trumpet snails and the ramshorn snails which were cleaning the rocks (everything else in the tank is presently clean except for the rocks).
I have used both lights recently, which has increased the algae on the rocks, because I was trying to get the plants looking better.
The plants aren't leggy and grow quite compact making me think that light is not the issue.
I have turned the rocks over to deprive the algae of light and this may be a solution. Also putting the rocks in the corners where it is less strong.
Any help would be welcomed.
Thanks Jerry

[RTR]

FYI, two 30% - 33.3% partials weekly =~one 50% partial weekly. Separated partials do not add the percentages, the residual "old" water must be calculated. See "Water Changes" and "Water Change Math" in the Article submission forum here. But that is a perfectly valid change schedule. I use it myself on several tanks.

If you have unwanted algae, the only solution is shading or lowered light. Nutrients and light -> algae or other plant growth - a basic fact of nature. You can't fool Mother Nature. You can use plants which will overhang the rocks and reduce the algae.

Just turning the rocks over is retuning the nutrients sequestered in the algae back to the water column. That is a no-win game.

HTH

[jeromecarlyoung]

Blimey! That's some very attractive mathematics there.
Just as long as my numbers (ammonia etc) are low then I think I'm ok.

I think the algae is going to end up in the water whatever I do with the rocks. I guess the algae is at least tying up excess nutrients. If I lower the lighting then then the plants may suffer so i will try not to do that.
My thought was that aquatic plants would strip out nutrients quicker than algae or at least compete for nutrients so lessening the algae.
I have these rocks at the moment pitched up with a peice of bog wood to form a triangle so the rocks could be rested on the deck where light will be less. Good stuff!
Thanks for your help and all.
-Jerry

[RTR]

Good vascular plant growth can out-compete algae, but if the rocks are unshaded, there is no higher plant to compete in that area and the algae will grow. Plus to out-compete algae, the nutrients have to be in the right balance for the vascular plants, and that requires either EI-handling or a heck of a lot of testing. That is too much cost and effort far a small simple tank.

Alternately, you could cover the rocks with Java Moss or cladiphora algae (torn-apart marimo or "moss" balls -which are not moss but algae. But that will hide the rocks, which I don't think you want.