Spirogyra algae help...

[Cross]

Encountered this algae in my cherry shrimp tank just recently.
http://www.theplantedtank.co.uk/alga...yra1-thumb.jpg


Around a month ago i had 1/3 of my canister's medium replaced with biohome. Realised something was wrong when brown algae started infesting on the tips on my hairgrass and spikey moss a week later. Tested my water and found a spike in ammonia and nitrate. Stumbled upon a dead cory corpse hidden somewhere within thick hairgrass! Had it 'buried' in our sewage system

NOW, after 2 weeks and a major trimming session for hairgrass, brown algae seem to have stopped manifesting, but comes something i have not encountered before. Initially thought it was hair algae, but it got longer and looked different. Later found it to be Spirogyra.

Water parameters are fine,
0 ammonia
0 nitrite
~0 nitrate
ph6.5


Tank specs:
2ft 5plan tank
setup 4months old

Filter:
Eheim 2234
(2layers eheim substrat pro, 1 layer biohome which replaced exsisting substrat pro ~ 1mth ago)

Lighting:
72W PL 8hrs daily(4on4off4on)

Co2 injection @ ~30ppm using drop checker

Temp ~ 27-29

Fertilisation regime:
Wondergro Macro+micro each on alternate days
Excel daily

Weekly waterchange 50%

Current plants:
Hairgrass
Bylxa Japonica
Spikey moss on dw
HM
HC

Fauna:
~80 cherry shrimp
2 oto

Anyone encountered this 'pesty' algae? did many manual removal as well as removing plants that it grows on but comes back after a few days!
Any help is greatly appreciated!

[Shadow]

reduce your light, manual removal and increase your water change frequency. Yamato shrimps usualy eat it.

What substrate did you use? do you use kH = 4 on your drop checker?

[Cross]

using gex plant soil. yup using kh4 water in drop checker. Finding it hard to remove it completely. seems to stick really well on the plants affected