constant low pH

[blazingazn]

i have a 30 gallon, low tech planted tank and for the past month, i've been having a low pH reading, around 6.0. i've tested every rock and equipment, thinking something new i put in affected the pH. but everything i tested yielded a reading of 7.0, which is the same reading as the tap. i've been constantly changing the water a little bit at a time. ammonia and nitrites are at 0ppm, while nitrates are around 5ppm (i know its on the low side for a planted tank due to the constant water changes, but i figured i should correct the pH problem first before being too worried about the plants) the fish dont seem to affected, as a matter of fact i even had a pair of GBR spawn for the first time. however, the low pH is having an impact on the amano shrimps and pond snails in the tank. the snail's shell is brittle and paper thin while the shrimps dont look too healthy. should i opt for a kH/gH testing kit or just get crushed coral to put into the HOB filters?

[Riiz]

I would go with the crushed coral idea, and also look into making your snails some snail-jello, to help with restoring calcium.

[DrNo]

Quick question first... when you measure the pH out of the tap, has it been sitting out for 24 hrs first? Dissolved gases interfere with this reading and need time to off-gas before an accurate reading can be taken.

[nfored]

I had the same problem, I added about 30 or 40 lbs of live rock from my friends old SW tank.

Withing 1 week my pH was locked at 7.8, this is the same as the crushed coral, after a water change my pH spikes to 8.4 - 8.6, but within 12 - 24 hours is right back at 7.8. My Tap water is past 8.8 pH. I know this stuff works because I used to use pure RO water with no additives, and was still able to raise the pH from unstable 6 - 6.2 to a rock solid 7.8

I tried useing seachem nutral regulator, and well I would have been better of buying a lotto ticket. That stuff only rasied my pH from 6.0 (maybe even lower) to 6.4 with a double dose over 2 days.

[blazingazn]

Quick question first... when you measure the pH out of the tap, has it been sitting out for 24 hrs first? Dissolved gases interfere with this reading and need time to off-gas before an accurate reading can be taken.

i measure the water right out of the faucet AND 24 hrs later just to be sure. also, tank water has been around 7.0 for about 3 months until last month when it just dropped

[Mgamer20o0]

get the test kit. there has to be something effecting the water.

[blazingazn]

i have corkscrew val in my aquarium, i read somewhere that these plants suck up the carbonate buffers out of ur water. is this true? maybe this is the reason for my problems...