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Re: Tank Problems

On Fri, 7 Jul 2000, Jeff Thomas wrote:
> Ive been a subscriber to this list for a couple years now, but this
> is my first posting.  My tanks (the plants) havent been doing as well
> as I had hoped lately, and I was hoping for some advice.  I have two
> 29-gallon tanks with Aqua-Tech power filters hanging off the back of
> each (running at their slowest speed) with filter media but no carbon.  
> Both tanks are 78 degrees.

<edited for brevity>
> Tank 1 also has a power head with DIY CO2...  Its lighting consists of
> three 20 watt fluorescent bulbs (2 Chroma 50
> s, and a GE Plant & Aquarium bulb) running 12 hours a day.  Fish are doing well,
> but I am battling black-brush algae.  The e. densa is growing very well, and
> is quite thick at the top.  I have to trim it back every week.  The swords are
> just maintaining their selves.  The java ferns
> are very small and get dark spots on the leaves.  I do have some Jobes plant
> spikes pushed under the swords and crypts, and I fertilize daily with PMDD (1.5ml,
> over the last few weeks I added KNO3 in the PMDD) and occasionally with Flourish.
>  I also add < teaspoon of K2SO4 twice a week and during a water change.  I change
> 1/3 of the water every other week.  I correct the Ph of the water with < teaspoon
> of NaHCO3 during water changes.

Jeff, this sounds to me like there may be a couple problems.  Slow growth
in the swords and the nuisance BBA suggest to me that your lighting may be
a little low and your CO2 and fertilizer regime not quite up to what you

Your lighting at about 2 watts/gallon is nominally OK, but if you have low
ballast factors, a cloudy glass cover or if you let the E. densa or other
plants get too thick at the top the result will be light that is too dim
for good growth.  See if you can identify the exact problem and fix it.

Java fern grows as you describe in one of my tanks.  I attribute that to a
poor nutrient supply in the water column.  The KNO3 that your recently
started might help.

Your water is a little (!?) strange and adding CO2 will be problematic
until you can do something about it.  More later.

The only algae eater in your tank is the lonely clown pleco.  You may want
to relace some of your current stock with a variety of algae eating fish.
In my experience the clown may damage your plants, so you may want to find
him a different home.

> Tank 2 had the same lighting, but a storm took out the dual bulb strip, and
> currently I only have a single Chroma 50 on the tank...  It has the
> same substrate as above (also about 1 year old), and
> no CO2.  The crypts have actually done better with the lower lighting.  Overall
> this has proved to be a less that spectacularly tank.  Water is changed as above
> although I did add about 1 teaspoon of sea salt per 10 gallons of water during
> water changes.  I have been slowly lowering that recently to see what happens.
>  (I have had good growth in the past in this tank).

Many of the same comments on the first tank also apply here.  Recent slow
growth could probably be explained by your lighting problem.  If you want
to get much faster growth (some people don't, as it can double or triple
the required maintenance) then you will need to add CO2 and accompany it
with appropriate fertilizer.

> Here are my most recent tank parameters taken in the evening:
>               Ph      Fe      P       Nitrite	Nitrate	Kh     Gh
> Tank 1       6.7     0.1      0.2     0       <2.0    0       7
> Tank 2       7.1     0.01     2.0     0       <5.0    0      11
> Tap           <5     0        0.001   0.01     2.5    0       5
> Water is taken unfiltered from a well.  I believe that the water contains a
> good about of CO2, as I get periling after a water change, both on the plants
> and the glass.  Im not sure if its real periling from the plants or not, or
> just the CO2 escaping.

It's probably real pearling.  Your well water may indeed by high in CO2
but it's unlikely that your well water contains enough CO2 that it will
form bubbles underwater.

There is something strange about your well water.  The 0 KH and the very
low pH are problems. I can't tell how comfortable you are with this water
or how much you might already know about the water, but if it were my well
I would want to know more then the info in your table.

For using your water in an aquarium with added CO2 you might try pumping
the water into a container (e.g. Rubbermaid garbage can) and aerating it
to drive out excess CO2.  That should cause the pH to rise.  If the pH
doesn't rise then you might have an organic acid in your water that is
forcing the pH low.  A carbon filter might remove that but I really
can't provide advice there.

Add carbonate or bicarbonate as a buffer.  Potassium bicarb, shells,
marble chips and a number of other sources can be used in place of NaHCO3.  
You may want to avoid shells, marble chips or other calcium sources
though, as your GH is already sufficient and those will raise it higher.  
Try to get 3 or 4 degrees of KH.  If you have an organic acid in your
water then it could take quite a bit of bicarb to get the KH up.  
Increasing the KH will also increase the pH.

Once you have and can keep enough KH in your water, then you can use it in
your tank with added CO2.  With 3 or 4 degrees of KH in the water a yeast
CO2 setup should be sufficient to pull the pH down to comfortable values.
I suspect that your present system on the first tank may not be adding
very much CO2.  If it isn't then you may want to reduce the surface
turbulance and/or find some other way to get the CO2 dissolved in the

Good luck

Roger Miller