What is this green slimy algae

[Lamie]

On the floating plants I have green slimy algae. Will it harm the fish at all?

 

[Essjay]

Photo?

 

[Lamie]

Thanks

 

[Byron]

Looks like cyanobacteria, the mass of it to the right of centre in the photo. High organics in the presence of light are the causes. Organics occur from the fish being fed (overfed?), and not maintaining adequate maintenance involving water changes, substrate vacuuming and filter cleaning. Too many fish for the tank would also factor in if relevant. The light may be on too long...plants at the surface obviously have algae or cyano issues more readily and reducing the duration may be necessary. But the organics load has to be cut back or cyano if removed will only come back.

 

[Lamie]

I've cut back the plants to half, added another piece of light gel over lcd lights and have cut down the light to 8 hours.

 

[Lamie]

If I leave a little bit on the plant will it grow from there?

 

[jaylach]

If there is a combination of light and nutrients algae will always grow.

Actually cutting back your plants could easily cause more algae as there will be less nutrients taken by plants leaving more for the algae.

Do you use plant nutrients, liquid form would apply more as to algae than root tabs? If so cut back on the dosage.

I have just recently gone to a fully planted tank and have found that you have to experiment with nutrients for plants as it is a fine balance. In my case I want algae as my Panda Garras are voracious algae and bio film eaters. I DO have what I think may be the same gunk as you but not within the water column. My LED lights are VERY close to the water surface and get coated with a slimy form of algae. I just use paper towels to wipe off the LED cover when I see strands of the gunk hitting the water. To cut back on the amount of this stuff that you have in your water column you could do something similar. Use a fine weave fish net and slowly scoop the stuff out. If you try this do it before water changes as the addition of the new water will break up and spread the stuff.

Also keep in mind that algae is not always a bad thing as long as controlled.

 

[Lamie]

It looked stagnant where the cyanobacteria was sitting. It started when I changed the lighting time and the intensity of the light. Before that I had bba which I would prefer. The cyano looked like a stagnant pond.
I haven't been able to grow any plants on the surface. Indian leaf fern got covered in gunk and the wisteria that cost $9 each last about one week. It's so frustrating

 

[Byron]

One needs to keep in mind that cyanobacteria is a bacteria, not an algae, and problem algae is a plant. The same basic conditions, being excess nutrients in the presence of light, can support both. Cyanobacteria is more a nutrient/organics issue, whereas problem algae can occur from either nutrient excess or light excess, or the reverse (insufficient nutrients or insufficient light for the plant species).