Pwc water chemistry match up

So I know you have I get makeup water for the pwc to be almost the same with the dt water... pH, salinity, temperature.

But how do I change the pwc water chemistry to match my dt? I know how to raise/lower salinity and temperature but how do I mess with pH? Also, how close do the params have to match?

Thanks.

 

unless you know one of your params are off, then you should not be messing with anything. also keep in mind that when you do a water change depending on what salt mix you use all the elements needed to keep a healthy system should already be present in the salt. personally this is why im a fan of coral pro salt by redsea. a little expensive but worth it.

 

Cool. So if the new water has a pH of 8.0 and my tanks water is 7.8 it's ok?

 

That degree of difference with PH is acceptable
depending on how much water you are changing

if your doing 10% - you will be left with 9 parts at 7.8 and 1 part at 8.00
which if you add and then divide by 10 - your new tanks PH would be 7.82
Which as you can see , is not a significant difference from what you had before

you can do the math for Calcium, DHK and Mag in the same manner

if you know what you have, know what the new is and know how much you are going to change

same scenario with salinity , if your tank is 1.025 and your mix is 1.026 and you change 10%
you would have 9 parts at 1.025 + 1 x 1.026 = new SG of 1.0251 ( Nothing to worry about basically)

obviously it is best to get them as close as possible, and the more water you are changing the more important that is


Steve

 

Awesome thanks

 

I don't quite agree with using weighted averages for pH. pH is a function of ONLY CO2 and alkalinity. So, if The alkalinity is roughly the same as in the tank and the water is fully aerated (it should then have roughly the same CO2 as the tank, assuming the tank is well aerated) then the ph has to be roughly the same. If you do a weighted average, you could be calculating a ph for the average before it is fully aerated. You can use a weighted average for alkalinity though and I would just go by that. It is much more important than pH anyways.

However, are you using tapwater? This can have ca and alkalinity, independent of your salt (as we as other stuff) and the amounts can vary day to do. So, it would then be even more important to test consistiently.

 

No I'm using rodi and coralife salt.

 

No such thing as a simple answer here just match your salinity and temp to that of your tank for a water change.