"Bob A" wrote in message
...
This is not really a question, unless someone has some specific advice, or
sees something wrong with what I'm doing here.


No reason why it shouldn't remain stable. However, you might consider trying
one of those Hagen yeast based systems - its designed for a much smaller
tank (15G) & so will not give you very high levels of CO2 in your 50G tank &
therefore not really affect the ph that much. I bought one a while ago to
put on a small tank (10G) which is now empty so 3 or 4 weeks ago I put it on
my 50 (USG). The plants were doing OK in there without it but there is no
doubt that its made a significant difference.

Any extra CO2 in the water is good and will make a difference.....

If you don't want to buy the hagen kit then you could persist with your DIY
but slow it down by adding some Calcium Carbonate (Baking Soda) to the mix
(in fact you get this with the Hagen kit - they call it stabiliser!).

You could also introduce some more surface turbulence via an Airstone or
redirecting a filter outlet to ensure that the levels of CO2 in the tank
stay lower - if you achieve that then your Ph will not swing about so much.

HTH

I.