low pH kill good bacteria in filter?

[Addie]

Wonder if anyone know what pH level will the good bacteria be killed? Or the bacteria can survive at very low pH?

This is because I have low pH in my tank (~5.5). My tank's kH is around 2dkH. I know the low pH is not due to high level of CO2 as I measured it without CO2 injection and the value is 6.0. It is from the soil I used. Cannot do much with the soil now except have to change water regularly.

Addie

[overdrive]

Hi Addie,
I think I might have the same problem like yours. I also hve a kH of 2 and my pH has always been at 6.4, but recently my pressure regulator went a bit haywire and started to inject CO2 until my pH dropped to 6.0 2 days after my whole tank became cloudy. I'm not sure whether its a bacterial bloom or an algae bloom or just due to the fact that the filter bacteria died from the low pH. I think that low pH do kill filter bacteria. Do advise guys. I've changed 50% of the water already but still the cloudiness remains.

[Addie]

overdrive, I just changed my water too, it turns cloudy and some fish died after comming back from work. I dont have a NH4 test kit else I should think that NH4 will be high if bacterial has been killed.

If NH4 is getting higher, the chances of getting algae will be high if I remember correctly from some reading before.

However, I cannot lower my CO2 injection as algae will bloom due to low CO2 ... which I make this mistake by lowering the CO2 too much. My glosso has some BBA within them but has been under control after increasing the CO2. I'm fighting with the BBA now by ensuring the glosso will grow faster and out bit the algae one day. I start to see some new leaves from some of the glosso. Wish me luck

I hope any expert here can tell me if good bacterial can survive if the pH is below 6.0. Anybody?

[Encriptic]

Addie, do not over inject co2, too low pH can weaken the plants, and let algae even overrule the plant.

[Addie]

Thanks for the advice. I have monitor the CO2 bubble rate to prevent it from lowering the pH too much. I use ~2 bps for a 4x2x2 in a bioball reactor.

[PeterGwee]

[quote:534edbe40c="Encriptic"]Addie, do not over inject co2, too low pH can weaken the plants, and let algae even overrule the plant.[/quote:534edbe40c]

Are you sure? 40%+ of plants dry weight is made up of carbon..it would take a substantial amount of CO2 to cause possible issues to plants but you are likely to kill critters first before that occurs. The low pH could be a problem if it were to go to 4 or below..but it is unlikely to occur if the KH were to really stablise at 2 or higher. Just make sure you keep a close eye on the KH when you use peat based substrates but the peat effect will even out after a couple of weeks or months once the substrate has settled down (Organic materials broken down by bacteria..Adding of mulm to the base of the substrate would have speed up the process but you fail to do so though.).

Regards
Peter Gwee

[Addie]

Adding of mulm to the base of the substrate would have speed up the process but you fail to do so though

Peter, thanks for the advice, I will monitor the KH to prevent pH fluctuation. What do you mean by "adding mulm to the base..."? Can you pls help to clarify?

[PeterGwee]

pH fluctuation is normal in a planted tank..especially the non-CO2 types. It does not harm the plants nor critters as many seem to think so. A pH crash would kill critters though if the KH were to bottom out due to uptake from some carbonate using plants if your CO2 is too low.

Seen what settles at the bottom of the canister filter? That is mulm...dirty stuff.

Regards
Peter Gwee

[Encriptic]

[quote:a5d8fbc4="PeterGwee"][quote:a5d8fbc4="Encriptic"]Addie, do not over inject co2, too low pH can weaken the plants, and let algae even overrule the plant.[/quote:a5d8fbc4]

Are you sure? 40%+ of plants dry weight is made up of carbon..it would take a substantial amount of CO2 to cause possible issues to plants but you are likely to kill critters first before that occurs. The low pH could be a problem if it were to go to 4 or below..but it is unlikely to occur if the KH were to really stablise at 2 or higher. Just make sure you keep a close eye on the KH when you use peat based substrates but the peat effect will even out after a couple of weeks or months once the substrate has settled down (Organic materials broken down by bacteria..Adding of mulm to the base of the substrate would have speed up the process but you fail to do so though.).

Regards
Peter Gwee [/quote:a5d8fbc4]

someone told me that when i was asking about some algae on my glosso, 1 dude said pile on the co2, then this fella told me that too low pH can weaken the plant so dont over inject.

[Qazwer]

Btw, wat is the soil or gravels that really cause the lowering of PH?

ADA ...???

[Heuer]

ADA will be one of them.

[Plantbrain]

Low pH is not an issue(this low or down to about 4.7 etc). It does not weaken plants from everything I've seen and know.

As far as the bacteria, no, again, you are growing plants here, they use the NH4 directly. Bacteria are playing a secondary role here anyway.

Not much to worry about.
Some Discus folks have issue but they also use lots of food and high bioloads and don't mind doing lots of frequent water changes........so they tend to rely much more on low pH's and NH4=>NO3 bacterial conversion.

Maybe they should get themselves some plants

I'd listen to the dude that said "more CO2".
Be careful, too much can kill fish so test it.


Regards,
Tom Barr

[Addie]

Thanks Tom,

Thsi ease my worry of killing the bacteria at low pH. I can continue to supply CO2 at this rate (or more as long as I mornitor the pH) and not to worry that the bacteria will die off and causes NH4 to increase dramatically.

regards,
Addie

[Plantbrain]

Grow plants, not bacteria.

Regards,
Tom Barr