How low PH needs to be to erode live rock?

[Polymate3D]

Hello everyone

Thread title says it all. I came home after a week away on holiday to have algae taking over and PH drop from my already low 7.6 to 8.0 Ph to now reading 7.4 and peaking at the end of the day at just 7.8. CO2 is high in the house and bugs everywhere, so trying working on a long term solution.

My aquarium has always shown rising calcium and Alkalinity over time, with salinity staying the same and no dosing of any kind.

Is it plausible the lower PH would allow the erosion of the rock, or is this just a silly thought process?

- Paul

 

[Randy Holmes-Farley]

Depends on the alk, but pH 7.7 and lower is the danger zone. The lower it is, the faster it can erode.

That said, sand dissolves slowly in mist tanks because degrading organic matter down in it lowers pH.

 

[Polymate3D]

Depends on the alk, but pH 7.7 and lower is the danger zone. The lower it is, the faster it can erode.

That said, sand dissolves slowly in mist tanks because degrading organic matter down in it lowers pH.

Thanks Randy for replying as always.

Alk is saying currently 10.5 and fresh batch of salt water is measuring 8.2. I was starting to wonder if the consistent uprise I find is the PH at night. Softies are okay but LPS are not as happy.

- Paul

 

[Randy Holmes-Farley]

If pH 7.4 is accurate, it is cause for concern. I’d verify it somehow and if true, work to raise it.

 

[Polymate3D]

If pH 7.4 is accurate, it is cause for concern. I’d verify it somehow and if true, work to raise it.

Thanks again for the info Randy.

I will get some of the water and aerate it outside and then test it and see how much difference there is. Will update the thread once I have done so for any future readers.

- Paul

 

[Polymate3D]

Salifert PH Testing

I said I would get back and with a fresh Salifert PH test kit, here are the results.

Got some pre mixed salt water from my LFS. Seems to be around 8.15 to my eye in person. This was is a shop with a open door all day so plenty of ventliation.

This is the exact same water, just a sample which has been left indoors with a pump circulating with airstone for around 5 minutes. Only a small 0.5L sample. You can clearly see its dropped into the 7.4 to 7.7 region.

And finally this is a sample from my EVO at the same time (middle of the day). Very clearly 7.4 or maybe even lower.


So ventilation is seriously needed, and I will be working on a refugium for it as well so even if I am away, there is something to try and tackle this.

Alkalinity BTW in the EVO with this reading came out at 10.9.

Conclusion

So from what I am reading and understanding, The CO2 indoors is drastically high (Member in house has phobia of bugs so is a challenge but a solution is being done). This is pulling the aquarium PH down drastically as well, which is resulting in the rockwork being eroded in part, and calcium and alkalinity rises because of this.

Soft corals don't seem effected due to there low demand on creating a skeletal structure, compared to the SPS which slowly dwindle, or slowly grow.

- Paul

 

[Randy Holmes-Farley]

if the Salifert test is accurate, I would endeavor to raise pH. :)