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Old 13-02-2006, 09:47 PM posted to rec.aquaria.freshwater.plants
NetMax
 
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Default My tank chemistry readings...how to interpret

"ah" wrote in message
...
I have used those Doc Wellfish water chemistry test strips a few
times...while I find them somewhat hard to use (some of the color
gradations are too slight for MY eye to distinguish between...), I
seem to consistently come up with the following readings:

Nitrates - 180
Nitrites - 0
Hardness - Very Hard
Alkalinity - 40
Ph - 7.8


So what does this info mean about my tank water quality


Nitrates and no nitrites means the tank is cycled (waste processing = waste
production). High nitrates (over 60ppm) is usually a sign of poor
maintenance (insufficient water changes) or old tank syndrome (excess
amounts of decaying organic matter, usually in the substrate and/or filter
systems). If you read up on old tank syndrome, they typically talk about a
pH crash (from the acidification exhausting the water's buffer). However in
water conditions where the buffer is high, such as yours (kH of 40 is very
high, 40dkH?), the symptoms manifest themselves in seemingly uncontrollable
nitrate levels.

and what
should I do to improve things???


Lack of water changes and old-tank syndrome are both related to maintenance.
Gravel vacuum, clean the filters, do more frequent water changes. This will
bring the NO3 levels down. Note however, that an NO3 level of 180ppm is
basically a thick organic soup, and if you were to suddenly move the fish
into a zero NO3 environment, the change in osmotic pressure would cause
their gill cells to explode. You will need to make the changes gradually.

Also, what effect would these kinds
of readings have on plant growth???


We're sure the plants aren't lacking NO3 ;~). Do you have any live plants
now? I would be curious to know what your general hardness is. With a kH
of 40, I think the gH would be even higher. There aren't too many plants
which can do well in very hard water environments, Hornwort and some
Echinodorous come to mind (this group will have better suggestions). I have
Swords in hard water, but I try to keep it under 16dgH. When my well
seasonally goes to 36dgH, I'm alternating water changes between my softener
and the well, to keep my total gH down, at the expense of a little more salt
(which the fish do not mind, but I can't say the same thing about the
plants).

Off-hand, if your hardness is greater than 40dgH, I would suggest you take a
look at silk plants.

If your hardness is around 40ppm though (about 2dgH) then the situation
changes considerably!!! but since you called it very hard, I suspect the
former.

I think your pH reading might be suspect. Pour a glass of tap water and
measure the pH. Then leave the glass on the counter to air a few days and
then measure the pH again. The first reading is false, affected by the
amount of gases you may or may not have in your water. The 2nd reading
after airing is your true pH. The reading from your tank is your current pH
(as affected by whatever is in there to affect it up or down). hth
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-Andy