I finally looked up some city water works reports on the Internet and
they show variously:

- total phosphates up to 0.74 mg/L
- total phosphorous 0.17 to 0.22 mg/L (different time period)

- alkalinity 29 to 31 mg/L

Ever since the later '90s I've had blue-green algae (BGA) problems,
although they can be kept within reasonable bounds by manual removal at
water change time. The start of BGA seems to correspond to about the
time the city started adding polyphosphate to the water as a corrosion
inhibitor.

Do people have simple suggestions of how to reduce or moderate the BGA?
Folks at work are suggesting a reverse osmosis system with subsequent
remineralization of the water, but I'd like to keep it simple.

- 90 gal Aquarium
- 160 or 200 watts fluorescent light
- Eco-Complete substrate
- many plant (crypts, vals, Rotala..)
- good stock of fish

No fertilizers are currently being added to the aquarium, although I've
tried potassium nitrate solution, various trace element solutions,
Jungle plant tabs and even Pond Tabs. No C02 system is used.

Thanks for all suggestions!

Steve

In article ,
Steve wrote:
I finally looked up some city water works reports on the Internet and
they show variously:

- total phosphates up to 0.74 mg/L
- total phosphorous 0.17 to 0.22 mg/L (different time period)

- alkalinity 29 to 31 mg/L

Ever since the later '90s I've had blue-green algae (BGA) problems,
although they can be kept within reasonable bounds by manual removal at
water change time. The start of BGA seems to correspond to about the
time the city started adding polyphosphate to the water as a corrosion
inhibitor.

Do people have simple suggestions of how to reduce or moderate the BGA?
Folks at work are suggesting a reverse osmosis system with subsequent
remineralization of the water, but I'd like to keep it simple.

- 90 gal Aquarium
- 160 or 200 watts fluorescent light
- Eco-Complete substrate
- many plant (crypts, vals, Rotala..)
- good stock of fish

No fertilizers are currently being added to the aquarium, although I've
tried potassium nitrate solution, various trace element solutions,
Jungle plant tabs and even Pond Tabs. No C02 system is used.

Add nitrate. BGA cannot grow in the presense of enough nitrate (30 ppm).

--
Need Mercedes parts ? - http://parts.mbz.org
Richard Sexton | Mercedes stuff: http://mbz.org
1970 280SE, 72 280SE | Home page: http://rs79.vrx.net
633CSi 250SE/C 300SD | http://aquaria.net http://killi.net

Richard Sexton wrote:
In article ,
Steve wrote:

I finally looked up some city water works reports on the Internet and
they show variously:

- total phosphates up to 0.74 mg/L
- total phosphorous 0.17 to 0.22 mg/L (different time period)

- alkalinity 29 to 31 mg/L

Ever since the later '90s I've had blue-green algae (BGA) problems,
although they can be kept within reasonable bounds by manual removal at
water change time. The start of BGA seems to correspond to about the
time the city started adding polyphosphate to the water as a corrosion
inhibitor.

Do people have simple suggestions of how to reduce or moderate the BGA?
Folks at work are suggesting a reverse osmosis system with subsequent
remineralization of the water, but I'd like to keep it simple.

- 90 gal Aquarium
- 160 or 200 watts fluorescent light
- Eco-Complete substrate
- many plant (crypts, vals, Rotala..)
- good stock of fish

No fertilizers are currently being added to the aquarium, although I've
tried potassium nitrate solution, various trace element solutions,
Jungle plant tabs and even Pond Tabs. No C02 system is used.


Add nitrate. BGA cannot grow in the presense of enough nitrate (30 ppm).


Thanks! I've tried adding potassium nitrate, getting the level as high
as 10 ppm on one occasion. Normally nitrate is close to zero.

Some of the rainbowfish appear stressed for the next day or two after a
nitrate addition, and I only add a little at a time. Should I very
slowly ramp up the nitrate over a month, using potassium nitrate
solution? Do you or others find that this stresses the fish? I have:

2 small pl*cos
2 siamese algae eaters
4 clown loaches
4 neon dwarf rainbowfish
1 large blueish rainbowfish
12 zebra danios
15 white cloud mountain fish
9 platies

Alkalinity in the tank is about 80 ppm, because of crushed coral used in
filter (tap water is very low alkalinity).

Based on your suggestion I will try to very slowly bring nitrate up to
30 ppm and see what happens. If the fish get stressed I'll do water
changes to bring nitrate down again. Any further comments are welcome,
thanks!
Steve

You could also try to bring that phosphate down by a combination of fast
growing or, ideally, floating plants and less frequent water change
since it seems phosphate comes from your water supply.

If you live in a more rural area, or a small city, you could have your
rainwater tested to see if it is fit. It has some risks, but I've heard
of various degrees of success using rain water, but DON'T use it if you
live near a moderately or highly populated city (too much contamination
from industries and transport)

Add nitrate. BGA cannot grow in the presense of enough nitrate (30 ppm).

Thanks! I've tried adding potassium nitrate, getting the level as high
as 10 ppm on one occasion. Normally nitrate is close to zero.

Some of the rainbowfish appear stressed for the next day or two after a
nitrate addition, and I only add a little at a time. Should I very
slowly ramp up the nitrate over a month, using potassium nitrate
solution? Do you or others find that this stresses the fish? I have:

I once screwed up and put 200ppm of nitrate in a tank. I took me a week
to notice and about 3-4 weeks for the plants to eat it all up. No fish
snail or any of the shrimp in that tank was affected. I keep my tanks at
30-45 ppm nitrate.

Ammonia stresses fish, not nitrate.

--
Need Mercedes parts ? - http://parts.mbz.org
Richard Sexton | Mercedes stuff: http://mbz.org
1970 280SE, 72 280SE | Home page: http://rs79.vrx.net
633CSi 250SE/C 300SD | http://aquaria.net http://killi.net

"Richard Sexton" wrote in message
...

Add nitrate. BGA cannot grow in the presense of enough nitrate (30 ppm)

Can you tell us why this is so?

In article , Dogma Discharge wrote:

"Richard Sexton" wrote in message
...

Add nitrate. BGA cannot grow in the presense of enough nitrate (30 ppm)

Can you tell us why this is so?

Algae must have stable conditions. Try to grow it alone sometime. Shocking
it kills it, 3 days of dark, nitrates and people fertilization from now
on has always got rid of it quickly for me.

If I see somes it invariably means I havnt been fertilizing that tank enough.

--
Need Mercedes parts ? - http://parts.mbz.org
Richard Sexton | Mercedes stuff: http://mbz.org
1970 280SE, 72 280SE | Home page: http://rs79.vrx.net
633CSi 250SE/C 300SD | http://aquaria.net http://killi.net

Richard Sexton wrote:

I once screwed up and put 200ppm of nitrate in a tank. I took me a week
to notice and about 3-4 weeks for the plants to eat it all up. No fish
snail or any of the shrimp in that tank was affected. I keep my tanks at
30-45 ppm nitrate.

Ammonia stresses fish, not nitrate.


120ppm killed about 1/2 of the shrimp I had for a 3 day exposure.

Regards,

Tom Barr

www.BarrReport.com

Ammonia stresses fish, not nitrate.


120ppm killed about 1/2 of the shrimp I had for a 3 day exposure.

Regards,

Tom Barr

Your shrimp are pussies, what can I say?

Rememeber also I was using an, um, "suboptimal" *cough*hobby*cough*
nitrate test kit so who knows if was 20, 200 or 2000.

The reagent didn't react at all the first 3 times I tested it
then 5 minutes later it turned very red, as in glow in the dark
red, and thta was only when I opened the cap to the #2 reagent vial,
when I actually put a drop in hot pink sparks began shooting out of
the test tube. I understand this to mean nitrates are "high".

By my math it was around 200ppm. I left it for 3 weeks then change
it mostly all out, an Echinoduris was getting weird. I've got pics
of these should be lethally exposed Ammano shrimp someplace. (Looks
around the room at pieces of computers) Yeah it's on that one
over there. Hmm...

I wouldn't say nitrates are good for freshwater algae eating
shrimp, but I'm not convinced high nitrates will kill all shrimp
all the time.

But I am also convinced also that as soon as you can measure any ammonia
then by that time you already have a dead pink shrimp someplace
in that tank. They are deathly sensitive to ammonia and ammonium.

--
Need Mercedes parts ? - http://parts.mbz.org
Richard Sexton | Mercedes stuff: http://mbz.org
1970 280SE, 72 280SE | Home page: http://rs79.vrx.net
633CSi 250SE/C 300SD | http://aquaria.net http://killi.net

Richard Sexton wrote:
In article ,
Steve wrote:

I finally looked up some city water works reports on the Internet and
they show variously:

- total phosphates up to 0.74 mg/L
- total phosphorous 0.17 to 0.22 mg/L (different time period)

- alkalinity 29 to 31 mg/L

Ever since the later '90s I've had blue-green algae (BGA) problems,
although they can be kept within reasonable bounds by manual removal at
water change time. The start of BGA seems to correspond to about the
time the city started adding polyphosphate to the water as a corrosion
inhibitor.

Do people have simple suggestions of how to reduce or moderate the BGA?


Add nitrate. BGA cannot grow in the presense of enough nitrate (30 ppm).


Richard Sexton's suggestion of adding significant nitrate appears to be
working. This weekend nitrate was up to about 15 ppm and the BGA seemed
to be starting to "melt". In any case it's not growing rapidly around
floating plants like it used to. I've added more nitrate with K and
trace elements, and nitrate should now be around 20 ppm. with more
additions to come.

Following up on Richard Sexton's suggestion by google searches, I found
that 10:1 N:P should inhibit BGA. Here's a reference:
http://www.nalms.org/lakeline/pdf/ll21-1_smith.pdf . 20 to 30 ppm
nitrate should give me N:P 10, considering the amount of phosphate
reported by the city.

Thanks Richard!
Steve

Steve wrote:

Following up on Richard Sexton's suggestion by google searches, I found
that 10:1 N:P should inhibit BGA. Here's a reference:
http://www.nalms.org/lakeline/pdf/ll21-1_smith.pdf . 20 to 30 ppm
nitrate should give me N:P 10, considering the amount of phosphate
reported by the city.

Thanks Richard!
Steve

No ratio will ever limit or help an algae in a planted tank, the issue
is not the ratio, the issue is limitation or toxicity, one or the
other.

Ratios have not show to be critical in agricultural research generally.
Limitation? Most definitely.

7:1 ratio is better if you want to use a ratio concept.
The issue he you had everything but the N.

The ratio can be 20:1(say 20ppm N and 1ppm P) or 5:1 N:P(5ppm N and 1
ppm P), plants will still grow fine.

This ratios are not critical, limiting levels are.

Regards,
Tom Barr



Regards,
Tom Barr