Hi Barry - welcome.
I'm also pretty new to the site - agreed - it's a great place to converse about this great Obsession..... oops! I mean Hobby (Gee I keep doing that).
I think the word is Aquarist.
I guess you are pretty familiar with the relations of
PH to gKH and
dKh. What surprises me about your stats is that your water is so soft and yet your
PH is so high. I guess this means that you are likely to see a precipitous drop in
PH (become more acidic) as soon as the Nitrates (form of Nitric Acid) build up. This is because with such soft water there is very little buffering. Not sure but may happen. Your Carbonate/bi-carbonate is only mildly soft so perhaps that may help to buffer. None the less I would watch very closely and would be more apt to add an acid buffer instead of
PH down (which is usually just a weakened form of Sulphuric or other Acid). I.e.,
PH down will not adjust your buffering but will bring the acid down quickly so when more acid is added via organisms it may drop even further.
Just a suggestion/chatting. The pro's around here may be able to shed some more light on the topic.
None the less, if you're interested Seachem makes an excellent acid buffer specifically for freshwater.
Yep - As I recall Soft water should be really good for the Tetras. Correct me if I'm wrong, but I recall that they come from the upper parts of the Amazon which is soft slightly acidic water.
Well - none the less good luck and remember - the more gallons you have the clearer the world becomes

, The more pints you have the worldlier the clarity becomes.
Tom
Tom