Ph Concern

alan3513 · May 6, 2009

I have two Fluval Roma 125 tanks set up but have vastly different PH readings. They both have different decor i.e. Tank one, has gravel substrate, a large piece of bogwood and a ceramic flower pot cave, this has a PH of 7.2. Tank two has sand substrate, a smallish piece of bogwood, a larger piece of mopani wood, and a coconut shell cave but has a much lower PH 6.5. My tap water is 7.2. The fish seem happy, my ammonia and nitrite are both zero and my nitrate is 15. I'm concerned that the tank will stall. Any ideas why their is such a large difference between tanks, would removing any of the decor from Tank 2 make any difference, and if not, if i add some crushed coral to the tank how much would i need ?, Thanks in advance for any advice, Alan

Bigbadbaz · May 6, 2009

I cannot see why the two tanks have a difference like that, try a large water change first and see if it comes back up, as for adding coral I use barnacles, when I was setting up my Neo. Multi tank I added a chunk of 3 at a time, waited a couple of hours for it to cycle and then checked ph. Add small amounts slowly or you could overload the system.

smbgpd · May 6, 2009

pH 6.5 tank: slightly acidic pH due to bog/mopani wood and coconut cave. Would be good for Amazonian / S american fish. Why would the tank stall? Its more likely to stall if you change things rapidly, if the pH is stable and the other paprameters are acceptable, choose fisgh that will thrive in those conditions.

Anna Robinson · May 6, 2009

The lower pH could be down to the wood but is more likely due to not enough water changes to keep it up - if you really want to raise it, you could try doing partial water changes more frequently than you do now. Perhaps this hasn't happened with the other tank because the load on the biological filter is less, or because the gravel substrate has calcium carbonate (shells) in it, which is helping to stabilise the pH.

alan3513 · May 6, 2009

Thanks for the replies guys. Bigbadbaz- Have done large water changes but the PH doesn't change. smbqpd- I've read on a few threads on this forum that when the Ph gets to around 6.4 the benificial bacteria can go dorman and can't process the ammonia, is this not correct ?. I'm worried if my Ph drops much further i could get an ammonia spike. As mentioned earlier the fish seem fine, i have various Tetras and some Corys. thanks again, Alan

alan3513 · May 6, 2009

Anna Robinson I do a weekly 25% water changes on Tank one and have been doing twice weekly 25% water changes on Tank Two, (the one with the lower ph) although this is only because the sand looks slightly dirtier due to the fact you can see the waste on the sand which you cannot see on the gravel. Both bi-loads are roughly the same, thanks Alan

smbgpd · May 6, 2009

alan3513 said:
Thanks for the replies guys. Bigbadbaz- Have done large water changes but the PH doesn't change. smbqpd- I've read on a few threads on this forum that when the Ph gets to around 6.4 the benificial bacteria can go dorman and can't process the ammonia, is this not correct ?. I'm worried if my Ph drops much further i could get an ammonia spike. As mentioned earlier the fish seem fine, i have various Tetras and some Corys. thanks again, Alan

Growth (ie replacement) of nitrifying bacteria is inhibited at pH <7.0, so provided your tank is cycled and you add no more bioload then your mini-ecosystem will remain in equilibrium ie death of bacteria equals replacement of bacteria.

Useful link here:

http

/www.bioconlabs.com/nitribactfacts.html