Matching water change parameters to tank?

[zack801]

I didn't want to clutter the forum with yet another thread but I'd like your opinions on this since I'm not great with figure these things out on my own. I have a 130 growout tank. I have been doing 30g water changes about once a month all at once. I'm using instant ocean regular salt and the only thing i do is use HCL to match the alk to my tank around 8.5dkh. I'm finding that each batch can very quite a bit with CA, ALK, MG. My question is; if i switch to doing weekly 10g changes would that be small enough to not worry about lowering alk, adding calcium to new water, etc? This is an all SPS tank so I'm trying to keep any swings to a minimum. My thought is that 10g is really small and there would be a negligible swing in any of the key parameters if i just add it? I appreciate any advice

Thanks

 

[KrisReef]

Ideally it might work, but I’ve found that tank changes and salt mixes don’t generally fit the “ideal” so I have to tweak some parameter during water changes.

I use a mixture of natural sea water and salt mix in my water changes, and I try to use water changes to slowly move my parameters towards the ideal numbers I use as targets for alk, Ca, Mg.

 

[saltyfilmfolks]

I never had any issue with IO and my tank alk at 8.
Before and after I started dosing.
Stuff grew like weeds.

 

[zack801]

I never had any issue with IO and my tank alk at 8.
Before and after I started dosing.
Stuff grew like weeds.

Did you ever test the newly mixed batches? I've found alk that approaches close to 10dkh all the way down to high 8's. I normally try to keep mine around 8.5dkh so I've been bringing it down in the new water as needed. How big of a water change did you normally do? I'm just trying to see if 10g in a 130g really would make any noticeable difference? @Randy Holmes-Farley usually has some magical calculations for things like this

 

[saltyfilmfolks]

Did you ever test the newly mixed batches? I've found alk that approaches close to 10dkh all the way down to high 8's. I normally try to keep mine around 8.5dkh so I've been bringing it down in the new water as needed. How big of a water change did you normally do? I'm just trying to see if 10g in a 130g really would make any noticeable difference? @Randy Holmes-Farley usually has some magical calculations for things like this

No. Never did. Never do.
He also reccomendation observation of the tank and coral.
Not always numbers.

 

[MickeyCT]

I've been using IO for years on my 225 and I change approximately 40 gallons every two or three weeks. I have never tested the new salt water and also never bothered to match parameters. New water gets added to the sump then pumped up to the tank. Water changing station is in the basement,. I've never had a problem. The new water only makes a very small change to parameters that are measured by my Apex.

 

[zack801]

I've been using IO for years on my 225 and I change approximately 40 gallons every two or three weeks. I have never tested the new salt water and also never bothered to match parameters. New water gets added to the sump then pumped up to the tank. Water changing station is in the basement,. I've never had a problem. The new water only makes a very small change to parameters that are measured by my Apex.

I’m talking specifically alk, calcium and magnesium swinging, mainly alk. Do you have a lot of sensitive coral in your tank?