ph drop

[reeferaddict]

That is pretty much a perfect level yep... the pretty much widely accepted range is 7 - 12 dKH... err to the higher side but not too much or you will get precipitation of carbonates and bicarbonates which will actually cause lower alk, and consequently pH... DO read the articles! While they are a lot to wrap your head around ... they will be absolutely invaluable to anyone hoping to have success in this hobby... I too refer to them all the time... (just come here and look for posts by Beverly, she must have posted them no fewer than a dozen times, which IMO is great because NONE of us can understand water chemistry enough!).

Calcium and alk ARE related, and both should be monitored extremely closely until consumption and replacement levels are established, and on a less frequent but regular basis thereafter... (including after adding anything like rock, clams, corals etc... i.e. anything with a calcifying skeleton...) Most importantly, don't come and see your pH at 7.8 and decide you must immediately raise it... everything done here must be done slowly and with patience... these problems do not occur overnight, and cannot therefore be corrected overnight without often negative consequences... the articles will tell what variety of products and/or chemicals will correct specific problems, and how much to correct at once.

As for test kits... IME buy ones that you will actually use... I bought a complicated set of kits and rarely tested ... then I bought cheap fast ones and I'm on top of this... (OK... before you all jump down my throat here - I actually have both kinds - and believe it or not the cheapies stack up... for example I use Aquarium Pharmeceutical Alk & Ca tests... Alk is accurate to +-1 dKH so if I'm at 10 I know I'm within the range - I have confirmed this with a Seachem kit - Ca I have an accuracy of +-20ppm and I shoot for about 420 knowing my range is 400 - 440, acceptable to anyone growing any kind of corals.)

As for the low circulation in the room I truly doubt this will have any real effect on pH ... how is your surface exchange though? Water circulation and surface turbulence is definitely necessary for proper gas exchange, but unless you have some kind of excess C02 effluent leaking into your room, the oxygen saturation levels of water can be acheived with any kind of air suitable for breathing.