Trapper
November 19th 04, 07:55 PM
Hi folks,
I'm grappling with green water, and I'm going to keep tabs on it in
this thread. Jump in with ideas, suggestions, and
what-are-you-thinking type stuff.
BACKGROUND:
My new 75 gal plant tank was clear, plants and 9 little fishies
totally flourishing, for about 2 weeks. Then the water turned quite
green in about 24 hrs. Substrate is flourite, light 260W CF. CO2
injected to pH 6.5/20ish ppm. Tank is pretty heavily planted with
stuff including dwarf chain sword, amazon sword, ludwigia repens,
eleocharis, elodea, baby's tears, 1-2 mystery plants. Dosed with
Seachem Flourish 2x in 10 days.
BACKGROUND ANALYSIS:
In the initial 2 weeks, I tested KH (2), GH (2-3), and ammonia (0).
Yesterday, 2-3 days into the bloom, I decided to test PO4 and NO3.
BIG surprise on that one:
NO3 - ZERO
PO4 - ~2ppm, almost the upper limit of my test kit.
ACTIONS TAKEN:
18 NOV: dosed NO3 to 15ppm; dosed K at ~1.5x dose (Kent's K)
19 NOV: change 10gal water (PO4-free reconstituted RO)
RESULTS:
19NOV: green water is somewhat greener; visibility 1.5 feet. Elodea,
Eleocharis, Ludwigia, and E. tenellus are pearling pretty profusely
(and seemingly more than before N/K addition.
DISCUSSION:
I found a couple resources online (including one or two at the Krib)
about appearance of green algal blooms in conditions of N and K
shortage, and P non-limitation. I had heard that NYC tapwater has a
bik P spike in it. Given my roughly 2-week history of excellent plant
growth, I began to wonder if my tank was in such a N/K-depleted state.
Testing revealed it was so.
My aim is to feed N/K for the plants, use RO-based changewater, and
eventually both reduce the P and boost plant production. I have no
physical filtration capable of physically removing the bloom.
--Trapper
I'm grappling with green water, and I'm going to keep tabs on it in
this thread. Jump in with ideas, suggestions, and
what-are-you-thinking type stuff.
BACKGROUND:
My new 75 gal plant tank was clear, plants and 9 little fishies
totally flourishing, for about 2 weeks. Then the water turned quite
green in about 24 hrs. Substrate is flourite, light 260W CF. CO2
injected to pH 6.5/20ish ppm. Tank is pretty heavily planted with
stuff including dwarf chain sword, amazon sword, ludwigia repens,
eleocharis, elodea, baby's tears, 1-2 mystery plants. Dosed with
Seachem Flourish 2x in 10 days.
BACKGROUND ANALYSIS:
In the initial 2 weeks, I tested KH (2), GH (2-3), and ammonia (0).
Yesterday, 2-3 days into the bloom, I decided to test PO4 and NO3.
BIG surprise on that one:
NO3 - ZERO
PO4 - ~2ppm, almost the upper limit of my test kit.
ACTIONS TAKEN:
18 NOV: dosed NO3 to 15ppm; dosed K at ~1.5x dose (Kent's K)
19 NOV: change 10gal water (PO4-free reconstituted RO)
RESULTS:
19NOV: green water is somewhat greener; visibility 1.5 feet. Elodea,
Eleocharis, Ludwigia, and E. tenellus are pearling pretty profusely
(and seemingly more than before N/K addition.
DISCUSSION:
I found a couple resources online (including one or two at the Krib)
about appearance of green algal blooms in conditions of N and K
shortage, and P non-limitation. I had heard that NYC tapwater has a
bik P spike in it. Given my roughly 2-week history of excellent plant
growth, I began to wonder if my tank was in such a N/K-depleted state.
Testing revealed it was so.
My aim is to feed N/K for the plants, use RO-based changewater, and
eventually both reduce the P and boost plant production. I have no
physical filtration capable of physically removing the bloom.
--Trapper