# Possible origins of Green slime algae?



## BBradbury (Nov 8, 2010)

Hello dz...

Any kind of algae will grow in water where there's dissolved food in the water. You can't get rid of it entirely, but you can control it. Keep the tank water cleaner by increasing the amount of water you change, reduce the amount you feed the fish or plants, add some floating plants like Anacharis. Avoid flaked foods with high phosphates. Keeping Corydoras is effective, they'll eat most types of algae.

B


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## Kathyy (Feb 22, 2010)

BBradbury said:


> Hello dz...
> 
> Any kind of algae will grow in water where there's dissolved food in the water. You can't get rid of it entirely, but you can control it. Keep the tank water cleaner by increasing the amount of water you change, reduce the amount you feed the fish or plants, add some floating plants like Anacharis. Avoid flaked foods with high phosphates. Keeping Corydoras is effective, they'll eat most types of algae.
> 
> B


Wow. Plants need nitrogen, phosphorus, potassium, calcium, magnesium and a host of minor nutrients. Many come from water changes and many come from fish waste. Generally potassium and iron needs to be supplemented even in low tech setups. If the tank isn't planted then the build up of nitrogenous wastes, nitrate, is easily removed by doing water changes as would be phosphorous waste. 

Corydoras are wonderful fish but they don't eat algae. Keep snails, otos, small plecos, platies, mollies, guppies, swordtails, rosy barbs, SAE if you want algae eaters in the tank.

OP, if your muck is cyanobacteria, aka blue green algae, then the cause could be your glorious plant growth has sucked all the nitrate out of the water and you actually need to add some! CB can fix nitrogen and survive where higher plants struggle. Perhaps the plant that has been used as a substrate for the algae is somewhat weaker in growth.

Make sure your plant fertilizer contains nitrogen and phosphorus as well as potassium and micros like iron. If it does then I'd increase the dosing, go through the plants and pull up the stems that are in bad shape, trim bottoms and rinse CB off the tops. Remove any yellowing leaves and if a stem has lots then pull it and trim off the bottom.


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## dzarren (Sep 5, 2015)

the algae that is forming is cyanobacteria. I would not call it blue green, it is really green. and no, a cory wont eat it, i dont think anything will eat cyanobacteria in freshwater systems. i realized something earlier today, these lights that i have on in, although quite bright, are very old. the bulbs are at least 3 years old, so i went and bought 2 new bulbs for this tank and hopefully i can alleviate this problem.
I was powerfeeding the gambusia to try to get it to match the bioload of the puffy, and i was using newlife spectrum flake food and blood worms so that might have contributed to the phosphate problem.


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## Kathyy (Feb 22, 2010)

You don't have a phosphate problem, you have a nitrate problem as in not enough of it. CB grows great if there isn't any nitrate in the water as plants cannot grow well without it.

Do clean up the bottom of the tank by siphoning off excessive debris but CB isn't caused by that so much as not enough nitrate and not enough water movement.


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