Brackish Planted Aquarium

My brackish tank has been flourishing as soon during summer here in Australia. Now it's autumn...
Anyway, in my tank these plants started popping out of nowhere, can anyone identify them?

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With all these plants growing, I've also got some hairy filamentous algae growing, patches of blue-green algae, and other small plants growing attached to the rocks. The algae is kept to a minimum, but does anyone know a good way of totally eliminating the blue-green algae? It's growing on top of the sand, rock, as well as on the hairy algae.
I've tried removing them by hand, and some break off and grow elsewhere... Will they eventually die as nutrients are taken up by the plants? Any methods without damaging my plants or organisms living inside the tank?

BGA is caused by:

low NO3 - aim for around 20ppm
ammonia spikes - any organic matter floating around? Is the tank heavily stocked?
Dirty filter - this links back to an ammonia spike. When was it last cleaned and how often do you do it?

I am not sure on the plants.

Probably best posted in the brackish or even marine section, as they look more like macroalgae rather than true plants. Look nice though, I've seen similar things at the beach and in marine sumps. Either the brackish or marine section should be able to tell you what type of macroalgae , maybe even the genus.

What SG is this tank kept at?

aaronnorth said:

BGA is caused by:

low NO3 - aim for around 20ppm
ammonia spikes - any organic matter floating around? Is the tank heavily stocked?
Dirty filter - this links back to an ammonia spike. When was it last cleaned and how often do you do it?

I am not sure on the plants.

Click to expand...

Thanks for your reply.
I had cleaned my filter a few days ago. Anyway I've measured the NO3 not long ago and it was quite low, under 0.5. The BGA has been there for months on end ever since spring. Which is over half a year ago.
The tank isn't very heavily stocked, and excess food is always removed. Strange because previously the BGA would disappear when plants started growing in the tank.

three-fingers said:

Probably best posted in the brackish or even marine section, as they look more like macroalgae rather than true plants. Look nice though, I've seen similar things at the beach and in marine sumps. Either the brackish or marine section should be able to tell you what type of macroalgae , maybe even the genus.

What SG is this tank kept at?

Click to expand...

thanks for your suggestion, I don't know what SG the tank is set to, Since its brackish the SG is continually altered. I get my water from the nearby river, so that's where the plants came from. Those fish also come from the same system, so they are used to it.