On Mon, 05 Apr 2004 13:41:35 GMT, "Michi Henning"
wrote:

Another one you might want to consider is Vallisneria.

Actually, speaking of Vallisneria, then I was just wondering after
this mention how this plant reproduced. With the notion here of course
that this is a nice plant for my aquarium, where more of them is not a
bad idea.

And so I went to take a good look at my Vallisneria, where I just
noticed that it is already reproducing. As this large plant has put
out two shoots in opposite directions near it's own roots, where these
have penetrated the gravel only a few cm away.

From those two points, then one new plant is already well established,
where a second one is just starting. Further more a third new plant
has started near the better established one.

Then there is a new shoot further out from these two, where I can only
assume that this first offshoot from the main plant has traveled
across and under the gravel for about 20cm so far producing new plants
as it goes.

So my one Vallisneria is already five Vallisnerias with no doubt more
to come. This I guess is all one plant so far, where I have no idea it
they will naturally separate.

Kind of a shame that I will soon have to break this up when I move
this plant and lots more to the bigger aquarium.

So I guess that this Vallisneria is taking care of itself without
myself having to do anything. Just the type of aquarium plant I
like...

Cardman
http://www.cardman.com
http://www.cardman.co.uk

"Cardman" wrote in message
...
On Mon, 05 Apr 2004 13:41:35 GMT, "Michi Henning"
wrote:


Well, you could try lots of plants,

I am giving that serious consideration, but then that enters a whole
new area of caring for plants as well. As until now I just have a
handful of plants and let them grow.

and slow filter.

What type?

I run two filters, an Eheim 2128 canister and an Eheim 2012
internal one. The canister is rumoured to contribute to nitrate
removal. Apparently, sintered glass contains enough small
pores for some anearobic bacteria to break down nitrates.
I personally don't know how much credibility this explanation
really has. But I know that other fishkeepers and some people
at my LFS who've been keeping fish for longer than I have
been alive confirm that slower filters are linked to lower nitrate
levels. For nitrate breakdown to happen, you need anaerobic
areas in the filter, so the slow filter theory makes sense at
least from that angle.

That will contribute
toward reducing nitrates. You also add a denitrification filter. From
what I hear, they are a bit finicky though -- the the flow rate too high
and they do nothing, and get it too low, and they put hydrogen sulfate
into the water. (H2S is toxic.) But such a filter may not be a bad choice
given that you have high nitrate levels in your tap water.

Yes, where I have already come to the conclusion that I will need to
add one of these to my shopping list in the near future. When high
Nitrate levels in the tap water is a new thing for me.

Aqua Medic make a rather nifty one. My LFS uses one of those for
a large marine tank. And he told me that you needn't buy the special
bio balls they sell you. Pure sulfur can be had cheaply from chemical
suppliers and does the job just as well.

Good at removing nitrates and not easily infected by algae.

Very true, when it is my third plant that I cannot identify that is
suffering some kind of black algae covering to it's leafs. I tried
cleaning this off the other day, but it is suck on there very well.

Sounds like black brush algae. See
http://www.aquaticscape.com/articles/algae.htm
for some pictures.

I had a feeling that you would mention CO2. :-/

Naturally! :-)

I have a feeling that removing Nitrate from my water supply is my
current best method for keeping Nitrate levels under control. As I
still doubt that these plants will be able to fully deal with the
Nitrate production within this aquarium.

A reverse osmosis unit really might be a good way to go. They are not
that expensive -- around US $130.00 here in Australia, and they do
a perfect job of removing the nitrates (as well as all other salts).

Cheers,

Michi.

--
Michi Henning Ph: +61 4 1118-2700
ZeroC, Inc. http://www.zeroc.com

"Cardman" wrote in message
...
On Mon, 05 Apr 2004 13:41:35 GMT, "Michi Henning"
wrote:

Another one you might want to consider is Vallisneria.

Actually, speaking of Vallisneria, then I was just wondering after
this mention how this plant reproduced.

Lateral shoots, as you discovered. They also get flowers. I've had
underwater male flowers on my vals a few times.

--
Michi Henning Ph: +61 4 1118-2700
ZeroC, Inc. http://www.zeroc.com

On Sat, 03 Apr 2004 21:33:29 GMT, "Michi Henning"
wrote:

My previous rambling...
pH = 7.8
KH = 15
GH = 20.5
NO2 = 0.01 mg/l
NO3 = 100 mg/l

Also, Myriophyllum is happer in slightly acidic and soft water.

Well my tank water will one day soon be this...

pH = 7.0-7.2
KH = 5
GH = 7
NO2 = 0
NO3 = 50-100 mg/l

You can see my more recent postings for the details, which makes for
water that may be more favourable to this plant.

Your conditions may well be too alkaline and hard for the plant to
thrive.

Maybe that is one reason why these two plants suffered a rapid death,
where only their core sections are now alive.

From what I have read Myriophyllum Tuberculatum is a little more
flexible in the water quality than what you seem to indicate, where it
just does not like the extremes.

Like my former extremely hard water.

(Even under ideal conditions, Myriophyllum Tuberculatum
is considered a difficult plant to grow and will not do well in many
tanks.)

Yes, I found that out, when I began searching into why these plants
were dying. Since it is a question of trying to save them, or having
them visit my bin, then it is best to see if I can save them first.

I am starting to think that this could be rather hopeless though.

And there they were doing so well in the pet shop with no real
maintenance sources, like a light, either. I think we know why that
is...

BTW -- you should try to get those nitrate levels down. 100ppm is
definitely on the very high side where it will be toxic for at least some
fish species.

My fish can live in much higher levels perfectly fine, where they just
become unhappy in a world where algae rules. So they are very happy
with anything between 50 and 150 mg/l, when algae growth is very slow
at this level.

Adding lots more plants will help in reducing nitrate
levels.

A nice idea, but what you do not mention is that plants in fact use up
very little Nitrate, which is why I would have to bed plants very
heavily for any beneficial effects.

And so there is nothing that I can really do when it comes out the tap
at 50 mg/l +-20% to begin with, where the fish pooping will only cause
it to go higher.

That is unless you know of some way to turn Nitrate into something
else that won't harm fish?

So my objective is always to try and keep Nitrate levels below 100
mg/l, when going above 150 mg/l poses a rapid algae problem. Like even
now I am starting to get a little algae growth on the glass again,
after I had scraped the last lot off.

Plants I am sure will help slow the Nitrate advancement to an unknown
degree, but at this time I have 7 White Mollies, 5 Red-Eyed Tetras and
2 other fish (not in my fish book...). And with the White Mollies at
least that is a lot of end Nitrate production.

In case you are interested, then I am soon to stock a load of varies
plants that are rated in the "easy" level and suitable for my water.

My shopping list is currently...

5 x Hygrophila Polysperma
1 x Anubias Nana
3 x Crinium Thainium
5 x Microsorium Pteropus
5 x (Assorted) Cryptocorynes

Since I am in the process of changing my water quality by a
considerable degree, then I will have to review these and make sure
that they are suitable for my new water.

Any comments in my 18 plant choice welcome.

My only issue at the moment is with these Crinium Thainium (onion like
plants), when they need lots of space. For my small 20 gallon tank
that would be impossible, but I will soon have my other 20 and 40
gallon tanks up and running. So one in each tank could have them
growing just fine in lots of space.

Cardman.
http://www.cardman.com
http://www.cardman.co.uk

"Cardman" wrote in message
...
On Mon, 05 Apr 2004 13:41:35 GMT, "Michi Henning"
wrote:

Another one you might want to consider is Vallisneria.

Actually, speaking of Vallisneria, then I was just wondering after
this mention how this plant reproduced.

Lateral shoots, as you discovered. They also get flowers. I've had
underwater male flowers on my vals a few times.

--
Michi Henning Ph: +61 4 1118-2700
ZeroC, Inc. http://www.zeroc.com

"Graham Broadbridge" wrote in message
u...
"Michi Henning" wrote in message
...

BTW -- you should try to get those nitrate levels down. 100ppm is
definitely on the very high side where it will be toxic for at least some
fish species. Adding lots more plants will help in reducing nitrate
levels.

At 100 ppm NO3 there is some evidence that plants themselves shut down at
normal (0.05 - 0.1 ppm) Fe and trace levels.

Ah, I didn't know that, thanks! Do you have any links?

Cheers,

Michi.
--
Michi Henning Ph: +61 4 1118-2700
ZeroC, Inc. http://www.zeroc.com

On Mon, 05 Apr 2004 21:40:25 GMT, "Michi Henning"
wrote:

"Graham Broadbridge" wrote in message
. au...
"Michi Henning" wrote in message
...

BTW -- you should try to get those nitrate levels down. 100ppm is
definitely on the very high side where it will be toxic for at least some
fish species. Adding lots more plants will help in reducing nitrate
levels.

At 100 ppm NO3 there is some evidence that plants themselves shut down at
normal (0.05 - 0.1 ppm) Fe and trace levels.

Ah, I didn't know that, thanks! Do you have any links?

I cannot say that I have ever seen that myself with my 100ppm plus
Nitrate levels. As even my Myriophyllum Tuberculatum (red) ones, who
due to my extremely hard water and low lighting, only went and turned
brown and died greatly back are now putting out some green shoots.

Kind of odd to have a naturally Red plant that is Brown and Green
instead, but there you go.

I will keep that in mind though, but I cannot see how too much Nitrate
food can ever be a problem. Maybe that depends on the plant species,
where that would be an unusual species.

So I would also be interested in further details, when it could be
something to watch out for. Nitrate at 100ppm is not that high as
these things can go, when my aquarium Nitrate levels would exceed that
level just before my weekly water change.

At most I guess is that I have grown plants in Nitrate levels of
250ppm plus before, but of course then they and everything else gets
attacked by algae.

One reason I guess why too much Nitrate levels in nature, with for
example sewage discharge will kill plants, when there is no one to
clean the algae off the plants.

Well my water guide mentions that Nitrate levels between 25 and 100
are normal aquarium levels, even if it also says that Nitrate levels
should ideally be kept below 25 to avoid algae growth.

Anyway, today I finally got around to ordering those 18 plants for
this aquarium and then a couple of plants to go in my other aquariums,
where I will be happy to report how my Nitrate levels change.

I can only hope for a Nitrate reduction, when then I won't have to buy
that more expensive Nitrate Filter, but I consider that a long shot.

Cardman
http://www.cardman.com
http://www.cardman.co.uk

"Michi Henning" wrote in message
...

Well, you could try lots of plants, and slow filter. That will contribute
toward reducing nitrates. You also add a denitrification filter. From
what I hear, they are a bit finicky though -- the the flow rate too high
and they do nothing, and get it too low, and they put hydrogen sulfate
into the water. (H2S is toxic.) But such a filter may not be a bad choice
given that you have high nitrate levels in your tap water.

I've had very little success with denitrification filters. About 10 years
ago I tried a
sera denitrator and that failed dismally - although that may have been
because I didn't
understand the process and my flow rate was probably too high.

Recently I tried a home brew filter using around 50 metres of tubing, but I
couldn't get
the flow rate correct to maintain an anaerobic culture. It just clogged up.

Best bet to reduce nitrate levels are lots of adequately fertilised plants
and water changes.

Even that has it's challenges :-)



Graham.

"Cardman" wrote in message
...
I would say at a crude guess that my Nitrate levels increase by about
50ppm per week, which is why I cannot leave it for more than a couple
of weeks without a good water change, when algae growth is explosive
if I do not change the water in that time.

Wow, an increase of 50ppm per week nitrate is huge :-)

Add lots of plants :-) The aim really is to balance the fish load with
plant load
so hopefully the nitrate can be utilised by the plants.

You can then spend time admiring the aquarium rather than slaving over it.

I prefer to have a deficit of nitrate, so I can add it when necessary
together with other
nutrients. That sure beats excess nitrates and phosphates which lead to
excess algae.

I have to add nitrates twice weekly to keep
the level at around 10ppm. Even if I dose the tank to 20ppm, three to
four
days later, it's back down to zero. The plants definitely have something
to
with this. I suspect (but don't know for sure) that there may also be
some
amount of anaerobic nitrate reduction happening in my canister filter
and possible in parts of the substrate.

Sounds like you need some more fish, where my White Mollies make for a
good example of the type that would be good at Nitrate production.

No No No :-) Don't do it :-) Add nitrate by hand rather than adding fish.

If you add fish you can end up with a extremely finely balanced system where
a single
nutrient deficiency can result in an algal bloom.

Only my opinion of course, but I like to keep the tank under *my* control,
rather than
attempting to correct imbalances caused by excess fish load.


Graham.

"Michi Henning" wrote in message
...
At 100 ppm NO3 there is some evidence that plants themselves shut down
at
normal (0.05 - 0.1 ppm) Fe and trace levels.

Ah, I didn't know that, thanks! Do you have any links?

I knew someone would ask for references :-)

Sorry Michi, I read it somewhere and it seems to agree with my
observations/experimentation, but for the life of me I can't find the
reference. From memory it was in relation to commercial cultivation of
aquatic plants. It may have been on a hydroponic site, but like I said I
can't find it at the moment.

Regards
Graham.

A few general comments.

First off, while common knowledge is that "hardness is bad", there has
been evidence of supposedly acidic loving plants flourishing in hard water
in nature and in tanks. Do a Google search on this newsgroup's archives
and I'm sure you'll find many many articles on the matter. That being
said, I think that focusing on hardness was really the wrong thing to
focus on. Of all your water problems, it is the nitrates that are of the
biggest concern. Plus mollies traditionally like hard water, so even if
they aren't showing effects now, it might appear in the future. Also, most
of the plants on your list would be perfectly fine in your type of water
as I have most of them in my 20 dGH tanks.

Now, onto the nitrates. Many of those denitrafying systems depend on
setting up colonies of anaerobic bacteria which will fix the nitrate out
of the water. Of course, the downside is you have a potential biohazard
sitting in that loop should something go wrong if those anaerobic bacteria
are of the sulfur sort. Hydrogen sulfide coming from the tank is not only
unpleasant, it can also be potentially life threatening. This leads me to
find alternative ways to fix nitrate out of the water in my own tap
situation (only 20ppm from the tap for me).

Now, on to the solutions I pondered for my own nitrate situation. First, I
stopped drinking the tap water. Nitrates are as bad for humans as they are
for fish. Then I considered an RO unit for both drinking water and
cutting the tap water on water changes, but being a poor student I really
didn't want to go that route. Bottled drinking water is plentiful in this
area, so I went with that for me, but it's a tad expensive for the fish.

For my tanks, I considered two approaches to removing the nitrates. One
was a vegetative filter. In this concept, you run the tank water through a
system with terrestrial, aquatic or bog plants planted in it. Of course,
you provide plenty of light overhead for them to grow rapidly. Many house
plants adapt well to growing in a hydroponic situation (roots in water)
and there are several which were said to be good at fixing nitrates, like
pothos/creeping charlie. Unfortunately, those house plants also happen to
be toxic to cats and I have cats who like to nibble plants, so I couldn't
go that route. Another plant said to be good was water lettuce, but I
can't find that locally (I believe it's listed as a "noxious plant" here
and therefore illegal to sell).

The second option was to heavily plant the tank with aquatic plants. I
went this route with also a heavy tolerance towards algae. Most of my new
tanks are algae wastelands to begin with but you know what? That green
string algae is great at taking up nitrates. Just a pain to pull out every
week, but it did a good job. If I could figure out how to keep it
contained, I'd set up a vegatative filter with just it. After a while, the
tank seems to reach a sort of equilibrium where the plants are better at
sopping up the new nitrates than the algae, then my algae problems
decrease to nearly nil. My similis tank took the longest to reach this
point, but that was mostly due to the similis digging up every plant
except the amazon sword, apogogeton bulbs and a few crypts that escaped
their destructive rearranging.

"Cardman" wrote in message
...
On Mon, 05 Apr 2004 13:41:35 GMT, "Michi Henning"
wrote:


Well, you could try lots of plants,

I am giving that serious consideration, but then that enters a whole
new area of caring for plants as well. As until now I just have a
handful of plants and let them grow.

and slow filter.

What type?

I run two filters, an Eheim 2128 canister and an Eheim 2012
internal one. The canister is rumoured to contribute to nitrate
removal. Apparently, sintered glass contains enough small
pores for some anearobic bacteria to break down nitrates.
I personally don't know how much credibility this explanation
really has. But I know that other fishkeepers and some people
at my LFS who've been keeping fish for longer than I have
been alive confirm that slower filters are linked to lower nitrate
levels. For nitrate breakdown to happen, you need anaerobic
areas in the filter, so the slow filter theory makes sense at
least from that angle.

That will contribute
toward reducing nitrates. You also add a denitrification filter. From
what I hear, they are a bit finicky though -- the the flow rate too high
and they do nothing, and get it too low, and they put hydrogen sulfate
into the water. (H2S is toxic.) But such a filter may not be a bad choice
given that you have high nitrate levels in your tap water.

Yes, where I have already come to the conclusion that I will need to
add one of these to my shopping list in the near future. When high
Nitrate levels in the tap water is a new thing for me.

Aqua Medic make a rather nifty one. My LFS uses one of those for
a large marine tank. And he told me that you needn't buy the special
bio balls they sell you. Pure sulfur can be had cheaply from chemical
suppliers and does the job just as well.

Good at removing nitrates and not easily infected by algae.

Very true, when it is my third plant that I cannot identify that is
suffering some kind of black algae covering to it's leafs. I tried
cleaning this off the other day, but it is suck on there very well.

Sounds like black brush algae. See
http://www.aquaticscape.com/articles/algae.htm
for some pictures.

I had a feeling that you would mention CO2. :-/

Naturally! :-)

I have a feeling that removing Nitrate from my water supply is my
current best method for keeping Nitrate levels under control. As I
still doubt that these plants will be able to fully deal with the
Nitrate production within this aquarium.

A reverse osmosis unit really might be a good way to go. They are not
that expensive -- around US $130.00 here in Australia, and they do
a perfect job of removing the nitrates (as well as all other salts).

Cheers,

Michi.

--
Michi Henning Ph: +61 4 1118-2700
ZeroC, Inc. http://www.zeroc.com

"Cardman" wrote in message
...
On Mon, 05 Apr 2004 13:41:35 GMT, "Michi Henning"
wrote:

Another one you might want to consider is Vallisneria.

Actually, speaking of Vallisneria, then I was just wondering after
this mention how this plant reproduced.

Lateral shoots, as you discovered. They also get flowers. I've had
underwater male flowers on my vals a few times.

--
Michi Henning Ph: +61 4 1118-2700
ZeroC, Inc. http://www.zeroc.com

On Tue, 6 Apr 2004 11:21:44 +1000, "Graham Broadbridge"
wrote:

"Cardman" wrote in message
.. .
I would say at a crude guess that my Nitrate levels increase by about
50ppm per week, which is why I cannot leave it for more than a couple
of weeks without a good water change, when algae growth is explosive
if I do not change the water in that time.

Wow, an increase of 50ppm per week nitrate is huge :-)

Well 7 well fed White Mollies who tend to do big long poos I am sure
explains most of this, but then I have had some plant decay as well.

Another problem is that my Power Head is blasting some of the food
straight down into the gravel. While I had some bottom dwelling
catfish this was not a problem and made for easy catfish feeding, but
this food is just extra Nitrate production these days.

I need new Catfish...

Still, my Golden Tiger Barb is helping out with this problem, when
during feeding time he locates himself at the bottom of the water
stream from the Power Head. And so he looks out for anything coming
downstream and soon has it eaten, but too much food at once has him
defeated.

Yes I could turn of my power head during feeding time, but well that
does require pulling out the plug.

My fish simply love my freeze dried Blood Worms, when some of my fish
do not even concern themselves over the usual flakes, but for these
Blood Worms they are all darting to the surface to get some.

I can see why that is, this being the most expensive in the freeze
dried food range. Damn fish think their royalty...

I am just wondering how they will like my live White Worms, when I
decided to give a live White Worm culture a shot. Seems to be doing
well so far, but another 5 weeks until fish feeding time.

Add lots of plants :-)

Yes, where I can only hope that this helps. Still, I will soon have
the White Mollies in the bigger aquarium once ready, where this will
spread out their mess somewhat.

I am sure that feeding my fish less would have them pooing less as
well, but too little feeding has its own problems.

The aim really is to balance the fish load with plant load
so hopefully the nitrate can be utilised by the plants.

And all those plants need a lot of care as well, or at minimum extra
equipment.

You can then spend time admiring the aquarium rather than slaving over it.

That would be nice, where I am left wondering if water changes can be
done much less frequently by keeping Nitrate levels in check.

I prefer to have a deficit of nitrate, so I can add it when necessary
together with other
nutrients. That sure beats excess nitrates and phosphates which lead to
excess algae.

I agree, but then a lot of my Nitrate problem is coming straight out
of the tap. As a weekly water change using Nitrate free water would
keep Nitrate levels around 25 to 50ppm.

Then of course extra plants would slow this rise further, or as I
would hope reverse it.

Sounds like you need some more fish, where my White Mollies make for a
good example of the type that would be good at Nitrate production.

No No No :-) Don't do it :-) Add nitrate by hand rather than adding fish.

As long as the Nitrate level is still in decline, then I do not see a
problem, when it will just mean less Nitrate needs to be added.

If you add fish you can end up with a extremely finely balanced system where
a single nutrient deficiency can result in an algal bloom.

Regular water quality testing would avoid that, where steps like less
feeding would help bring things back in line.

Only my opinion of course, but I like to keep the tank under *my* control,
rather than attempting to correct imbalances caused by excess fish load.

Just remember that aquariums are for fish, where if you want to grow a
few weeds, then I will give you a pot of soil. ;-]

So plants are nothing more to me than with creating better water
quality for my fish, where to be honest, then as plants go most of
these look damned ugly.

And so for real plants, then get a big pot and a few simple sunflower
seeds. ;-]

Cardman
http://www.cardman.com
http://www.cardman.co.uk

On Tue, 06 Apr 2004 09:49:36 GMT, "Michi Henning"
wrote:

"Cardman" wrote in message
.. .
On Mon, 05 Apr 2004 13:41:35 GMT, "Michi Henning"
wrote:

and slow filter.

What type?

I run two filters, an Eheim 2128 canister and an Eheim 2012
internal one.

Nice idea, when everyone should use at least a twin filter system.

The canister is rumoured to contribute to nitrate
removal. Apparently, sintered glass contains enough small
pores for some anearobic bacteria to break down nitrates.

I will have to look into that then.

Currently I have been looking into getting yet more equipment for my
two new aquariums, where I was very close to buying two more
undergravel filters and powerheads, then I changed my mind.

As I was looking into how you can put sand and an undergravel filter
together, where my solution was to get a short undergravel filter,
then to put the sand in the remaining 1/3rd.

Then I came across the good and the bad points for undergravel
filters, where although most of these do not apply to my system, but
there is the point about plants.

As of course it is harder to care for plants when almost everything is
being sucked away. So I began looking into other filter choices, where
an external power cannister filter seems most popular.

And so after looking around I am very tempted to buy the Fluval 304
external cannister power filter, which for this model can handle 710
litres an hour.

Tons more than what I would need for this aquarium, but increased
water throughput can keep the substrate in better shape.

My only bad view towards this is that it seems little more than a
glorified external sponge filter with a few extras at like 10 times
the price.

On the plus side, then it would allow extra room for more substrate
for the plants, then extra water for the fish.

I personally don't know how much credibility this explanation
really has. But I know that other fishkeepers and some people
at my LFS who've been keeping fish for longer than I have
been alive confirm that slower filters are linked to lower nitrate
levels.

All I have seen so far are the power filters, but I will certainly
look into the slower type. Although being so slow I wonder how they
can do a good suction job in the first place.

Maybe they don't produce so much Nitrates due to simply being bad at
the Ammonia to Nitrite to Nitrate cycle. Messy tanks in other words.

For nitrate breakdown to happen, you need anaerobic
areas in the filter, so the slow filter theory makes sense at
least from that angle.

This is going to need quite some research, when I can see
disadvantages to a slow filter system as well.

Aqua Medic make a rather nifty one. My LFS uses one of those for
a large marine tank. And he told me that you needn't buy the special
bio balls they sell you. Pure sulfur can be had cheaply from chemical
suppliers and does the job just as well.

Yes, I can see why.

Sounds like black brush algae. See
http://www.aquaticscape.com/articles/algae.htm
for some pictures.

Seems that I have at least 4 kinds of algae in my tank, what with that
Black Algae on those leafs, then my glass is effected by Brown Algae,
where I have a slimy Dark Green Algae on my petrified wood, where last
of all the long strangly Lighter Green Algae on the plants.

My water also has a very light green tint, but this is not a problem.

I see the recommended solution for my Black Algae is leaf removal,
which causes me a problem, when this plant has very few leafs to begin
with.

Still, maybe this algae could explain the death of these leafs, where
maybe this even came with the plant.

I will look into it, when I expect that this plant can live without
leaves for the short that before it grows more.

A reverse osmosis unit really might be a good way to go. They are not
that expensive -- around US $130.00 here in Australia, and they do
a perfect job of removing the nitrates (as well as all other salts).

I will take a look around, when apart from doing a good job, then this
is a question of price.

Cardman
http://www.cardman.com
http://www.cardman.co.uk