Question about changing water parameters & existing beneficial bacteria...

[Magnum Man]

so I have horribly hard water in my area, & when I started my tanks I used softened water from my whole house softener... tanks have been running for about a year... ( poor fishies ) anyway I'm in the process of blending in RO water, to the existing aquarium water, & continually testing the water parameters each 5 gallon of water change...

I realize if I did this too quickly it could effect my fish... but I'm also wondering about how my beneficial bacteria is going to be effected by a wide swing in the water ( a good portion of these tanks were soft water fish, & while my GH, in my tanks, having come from the softener have only been between 25 & 50... the KH & PH have been extremely high, assuming from the salt ions from the softener... after 4 - 5 gallon bucket water changes, with a day or two between them, finally those high numbers are starting to move...

so how is my BB going to react to these changes in the water???

 

[jaylach]

If the tank is a year old the bio film should be established enough to help protect the bacteria. Of course there ARE PH levels that can kill good bacteria but they can deal with a pretty wide spread.

The real question is what fish do you have and what PH they like.

You say that the tank is a year old and I take it that the fish are doing fine. Research your fish and find their PH range and, if it fits with your water, don't fix what isn't broken.

 

[Magnum Man]

Sorry… not a rookie here… been through all that… my water is so alkaline ( this whole area is… I’m a boiler operator, and trying to deal with the extreme alkaline water at work… right now I have my boiler chemical guy stumped ) any way, I got a lesson here on house softened water, and I’m trying to fix it now… even at 50% RO water on a 45 gallon tank,right now, my alkalinity is still as high as I can test… so my softer water fish ( typically like low ph ) that 45 still tests at 8.4 Ph, even though the GH is at 25 right now, which should be soft

Since I’m likely in uncharted waters right now ( not even sure if “normal” BB grows at over 8 Ph ) I’m not really worried about the ammonia, I’m doing a water change every other day, with RO to try to get the numbers close to where they should be

 

[Colin_T]

The beneficial filter bacteria will be fine with the change in water chemistry. They reproduce several times a day and will go through multiple generations between each water change and will adapt easily.