ph swings in pond. long post sorry, got carried away.

I have a small pond (100gallons its actually a large bath) with a lot of
plants and a couple of goldfish which have outgrown their tanks.

I added a filter, declorinated water, cycled the pond, put 2 fish in and
everything was fine, ph, nitrate and ammonia was perfect for a few weeks
with a bit of green algae on the sides.

Then i added the plants (oxygen weed) and the PH was swinging from 6.5 to 9
or even 10 in a daily cycle, a couple of weeks later I picked up some
ammonia on the tetra test kit (just about 0.3) and noticed a couple of the
fish were losing scales and not looking healthy. So they were bought back in
to their tank where they seem to be recovering well.

The pond has now been drained, painted with black bitumen, rinsed through 4
times, filters cleaned etc and is cycling as i type. but i need the plants
there to give the fish somewhere to hide as there are herons locally.

Now as i understand it, the PH swings are due to my water being too soft,
for a breakdown, see below
Hardness level SOFT No Standard Applies
Hardness Clarkes 3.6 No Standard Applies degree
Hardness 19 No Standard Applies mgCa/l
Aluminium 10 200 µgAl/l
Calcium 18 250 mgCa/l
Chloride 10 400 mgCl/l
Chlorine 0.16 mg/l
Coliform bacteria 0 0 no./100ml
Colour 1.55 20 mg/l Pt/Co
Conductivity 112 1500 µS/cm at 20
E.coli bacteria 0 0 no./100ml
Fluoride 922 1500 µgF/l
Iron 21 200 µgFe/l
Magnesium 2 50 mgMg/l
Manganese 3 50 µgMn/l
Nitrate 2 50 mgNO3/l
Odour 0 3 dilution No
Pesticides 0.0065 0.5 µg/l
pH 8.7 5.5 -9.5
Sodium 5 150 mgNa/l
Taste 0 3 dilution no.
Temperature 12.4 25 deg. celsius

Plumbing Metals

Zinc 8 5000 ugZn/l
Copper 14 3000 ugCu/l
Lead 7 50 ugPb/l



The PH of my water is actually 7.5 not 8.7 as above.

I`ve tried to get into understanding the various types of hardness and am
stumped as everything that changes the hardness also seems to change the PH,
I`ve been told to add bicarbonate of soda, but wouldn`t this push the PH up?
LFS suggested calcium carbonate, wich was quite intimidating until i
realised he meant chalk. What can i add that will stop the PH swings without
affecting the PH of my tapwater too much?

Also will marginal plants affect the ph like submersed plants? (i suspect
not as the leaves are out of the water, but I don`t want to go and buy them
and find out i`m wrong

One last thing, how long will a bucket of water take to dechlor with a 4"
airstone in it? I`ve been leaving it for 24 hours and changing a bucket a
day in the pond and 2 buckets a week in my tanks. Would it be safe to do 12
or even 6 hours per bucket? I don`t use dechlor as i don`t like using
chemicals unless i truly have to.

--

Aeration doesn't remove chloramine so that may be why you saw ammonia.
That pH swing is a bit much for overnight CO2. You could add sodium
bicarbonate to give a bit of KH to buffer the pH but my tanks run at pH 6.4
with less hardness than yours ( 3 k, ~10 GH) and I just keep a piece of
tufa rock in the filter box to hold up the kH a couple of degrees.
A bit more surface agitation to enable CO2 to escape may do the trick ;o)

Sue

"Sue" wrote in message
...
Aeration doesn't remove chloramine so that may be why you saw ammonia.
That pH swing is a bit much for overnight CO2. You could add sodium
bicarbonate to give a bit of KH to buffer the pH but my tanks run at pH
6.4
with less hardness than yours ( 3 k, ~10 GH) and I just keep a piece of

I agree, My tanks are fine with the same water as the pond, even with plants
in them (the same plants as in the pond). I think the fact that 1/3 of the
pond is in direct sunlight at midday and that the pond/bath was white really
boosted the plants growth and also their effect on the water. My tapwater
doesn`t have chloramine, only chlorine. (chloramine forms when chlorine and
ammonia are mixed?)

tufa rock in the filter box to hold up the kH a couple of degrees.

What is tufa rock? (remembers google) Oh, i see... ignor last question...
does it push the ph up much?

A bit more surface agitation to enable CO2 to escape may do the trick ;o)

I have plenty of water agitation, the 100gph pump that runs the gravity fed
filter goes into a fountain and there is a large airstone in the pond to
move water bottom to top.
I think my problem is that I had too many plants for such a small body of
water. And that my water is too soft.

thanks for the reply tho.

further to this... would this
http://members.madasafish.com/~graha...uttlebone.html
be okay to use to harden the water in my pond?

chemical constituents of cuttle-bone a calcium carbonate, sodium
chloride, calcium phosphate and magnesium salts. Will any of the above
constituents adversly affect my goldfish?