Brand New here -- John from Strathaven, southwest Scotland
tapwater here very soft 7.2pH NO2 = 0 NO3 = 0 2degKH 4degGH

QUESTION ......................... low KH in soft water - can you guide me further?

I have Z.danios, Glowlight and Xray tetras, pair dwarf gouramis, brochis splendens and corys trilin in 25 and 20 gallon tanks at 78deg each with ---
internal Fluval3 foam powerfilter, powerhead driven undergravel filter (with cupful of cockle shells in gravel), 2 x 25W lights
weekly hoover gravel with 4gallon water change; adding filter Bacteria Boost and Tetra "Easy Balance" (OK - lazy, lazy!)
fortnightly plant food
monthly rinse filter foams
Tanks are/have been stable for many years at 6.8 - 7.0 pH, NO2 = 0, NO3 = 0
3degKH --- but only measured recently

My problem..................?
I recently aquascaped with many more plants - mostly A. Swords, and bogwood caves for the corys
and planned to buy a simple sera "CO2 Start" unit for the plants

fishy website Quotes
FWQ1 " water below 3KH is unstable "
FWQ2 " soft water....if planted must raise KH to 3-6deg "
FWQ3 " my KH=1, pH6.6.........so cannot use CO2 "

so..........
Question 1............ with my low buffering, will the extra CO2 released by many plants cause a pH crash - read on....

FWQ4 " 1tsp baking soda raises 13galls by 4degKH "
some FAQ pages from a fish web years ago state - 1/2tsp per 100L raises KH by 1dH "

Ok .....armed with info.......I bought baking soda - BUT very wary of just chucking into my tanks, a couple of "home-brew" experiments

TEST 1 -- to raise KH
2gallons tapwater pH7.2 2degKh
added 1ml baking soda pH7.2 6degKh
added another 1ml pH7.4 11degKH ........... so it appears to work

TEST 2 --- effect of acid on pH ---- from nitrification and CO2?
the aforementioned website said to use hydrochloric acid (yeah - right) so used vinegar (acetic acid?)

sample 1000ml from tank pH7.4 3degKH
added 1drop (yes only 1!) pH6.8
added second pH6.4
added third pH 6.2 or below

PANIC NOW!
Question2.......... Does this mean I have NO buffering and the pH can crash at ANY time?

Question 3......... should I add 1ml soda to my weekly changes and so gradually increase KH?

Question 4......... adding soda will raise pH - maybe this will be balanced by CO2 from plants

Question 5......... should I stay away from adding a CO2 generator?


well............all probably very basic but I'd like prevent any pH problems
many thanks for your time
best regards, John
[email protected]

FWIW
after using TetraAqua "AquaSafe" de-chlorinator my tanks dropped by 0.5pH
A VERY helpful contact = Dave Hulse B.Sc. (Hons), M.Sc. Tetra Club Help Desk http://www.tetra-fish.co.uk/
advised their product was "slightly acidic" and to be vigilant when using it below 2degKH
_________________
John