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green water

1831 Views 2 Replies 3 Participants Last post by  cS
just got them in my 30L tank of h.c . probably too much light, co2 and no3...
can i battle them without UV and without chemicals? how?
its a new tank (after the nitrogen cycle) full of h.c that i dont want to loose so afraid to darken it...
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Hemianthus callitrichoides is tougher than its diminutive appearance. I doubt that a black-out will kill it. I don't own a UV sterilizer or a diatom filter but this is what I do when confronted with green water.

(1) Perform a 90+% water change and clean filter.
(2) Black out: NO light is allowed to enter the aquarium.
(3) 90+% water change.

This usually takes care of it in 1-2 days. The initial 90+% water change greatly reduces the algae's biomass, making for less time needed during blackout to kill them all. The ensuing 90+% water change may be overkill, but I like to do it anyway for insurance.


I usually get green water when my plants are SERIOUSLY in bad shape, lending credence to the theory that NH4 accumulation + high light = green water. In your case, is there any other plant in this tank beside the H. callitrichoides?
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