Algae growing on my GSP


Harlequin Shrimp
I got this algae growing on my GSP :angryfire: I can't tell what kind it is..
It looks exactly like grass growing in the tank.. I've had hair algea and Bryopsis before (infact they are both growing elsewhere in the same tank right now) and I just got rid of diatoms. This algae looks completely different from hair and bryopsis IMO, its not even spreading... its only growing taller and taller... I have 1 mexican turbo snail in there who amazingly decides to get himself stuck in the rock where he can't get back out after adding him... probably isn't even alive...

I have harlequin shrimp so they didn't help with the phosphates and such.. I managed to rid the diatoms but the algae is still an issue as it still is thriving.

Also notice the 5 GSP heads that opened? those are the only 5 that opened since I got them... which was about 1 month... They opened completely once when I first got them and now they are all closed except these ones...there was like 100s of them on this rock before... the purple base for them all is still there tho.
Sorry for the Poor Quality




reefin chef
the kind doesn't matter the remedy is the same... you have phosphates.. are you using rodi water or tap.. how often and what do you feed.. what kind of lights and the kelvin rating.. are you dosing anything.. carbon/gfo...


Harlequin Shrimp

10 gallon
8 lbs. live rock (4.5 lbs. premium Decorative Live rock with all this macro and sponges growing on it)
20 lbs. live hawaiian black sand
Marineland penquin biowheel-100
A cheap tetra brand heater.
Aqualight HO 30" dual T5 (going to be upgrading to DIY Rapid LEDs)

Harlequin shrimp pair,
2 sexy shrimp
1 mexican turbo (for the algae..)
2 bumble bee snails.
2 nassarius
1 pom pom crab
70 or so hitchhikers... :eek: (Fire, bristle, spaghetti worms, brittle stars, whelks.. you name it...)

Frozen Starfish leg for harlequin shrimp
3 PE mysis shrimp

Ammonia: 0
SG: 1.023
Ph: 7.9
Nitrate: 0 or 10 I can't tell good... (API master test kit)

I'm building a refugium for the tank that will house a back-pak skimmer.


New member
1st: what is the photo period? (maybe too much light)
2nd: frequency and volume of water change?
3rd: pH is low
4th: do you monitor temp?


Harlequin Shrimp
temp is on a automatic tetra heater (self programmed at 78... thermometer says 80...(I think it says 80, its orange on 82 and green on 78.. one of those outside digital strip thermometers that stick to the glass)

Weekly 2 gallon water change.

Light on when I get up (usually 10AM-12PM)
And off when I go to sleep (usually 11PM-1AM)

Too much light I know... I'm going to have timers on for when I upgrade to rapid LED.


reefin chef
deff to much light.... cut the light cycle down

you haven't mentioned the water source yet... if you are using tap test it for phosphates... and also check your unicipal water supply.. may be some other silicates or minerals that feed phosphates


Harlequin Shrimp
deff to much light.... Cut the light cycle down

you haven't mentioned the water source yet... if you are using tap test it for phosphates... And also check your unicipal water supply.. May be some other silicates or minerals that feed phosphates

I'm using RO water.


Harlequin Shrimp
Ok, I got a timer on the light set to turn on at 11AM, and turn off at 9PM.

I also, by hand, ripped off as much as I can. Since I got my 125 gallon building.. my lfs got in a really...really.. tiny yellow tang.. I figured I'd get it now since they munch on algae, and just add it to the 125 whenever its done cycling.

Gill again

New member
If it were mine I would take the GSP out and hand clean the piece with a soft brush. I had a small hair algae issue in a 90 gal that turned into a nightmare. Well I have GSP and the algae attached itsel and seemed to affect the polyps. After cleaning they were mad but fast recovered and started growing again. I think you have addresses the lighting issue I would say take as many pieces out of the tank when you are managing the algae. I think my mistake was allowing pieces to drift freely in the tank and it spread like wildfire.


Harlequin Shrimp
Thankfully, the algae went away about a month ago from some astraea snails cleaning it up. I still don't notice anything opening.. I see a few more but those look like its spreading more and the rest of the colony died-off.