Help with tank parameters/additives?

[LesPoissons]

Hi everyone,
I just started tracking my tank's parameters more closely so I can identify what needs improving. (I dont have a ton of coral growth or color) My understanding of the interactions of elements is not perfect, and now after reading a ton of research- im overwhelmed by conflicting information. so I was hoping for some straight forward advice on what to do to keep things balanced. I know there is a wide range of what is "ideal"- my tank is a 220 reef w about 20 fish and more inverts, kept at 79 degrees, with 30 or so small frags and corals (largest is maybe 4"), mostly lps with some sps. I use 1 bag of regular IO + about 1-2 cups IORC per water change.
Ex:
Beginning values------> 2 weeks later
ph: 8.2/8.25 -----> 8.2/8.25
Nitrate: 0-3 -----> 0-3
Phos: 0-0.05 ------> 0-0.05
Mag: 1215 -----> 1100
Ca: 410-----> 410
Kh/Alk: 8.6/3.08 -----> 7.3/2.6

It seems like the only things that dip are magnesium and alk. Im trying to see if I can back off on water changes since doing them religiously every 2 weeks for 3 years. They dont seem to be necessary for exporting nitrates/phosphates and if Im only doing them to refresh trace elements and other depleted elements- perhaps I can just use additives?
I have a bottle of kents magnesium, Red Sea ABCD, and Coral Vite that I have yet to use bc I dont want to start throwing things in arbitrarily. Are my values over all okay? My ca level is fine, how do I raise alk without ca or ph increasing or decreasing? Am I safe to dose magnesium? Other thoughts?

Thanks reefers!!!

 

[GoVols]

Your tank looks good!!

If your not having to dose for cal or alk (intake), then don't dose the Red Sea A, B, C and D colors.

 

[KrisReef]

Get some Mag and add that into your water change to bring it up to 1360-1400, and put some baking soda in your top off water and you should be good to go.

 

[LesPoissons]

Thank you! Will baking soda affect the ph?

 

[Billldg]

You can use sodium bicarbonate, it will raise your alk and it will not raise your ph. It actually will temporarily lower your ph for an hour or so.

 

[RJinPV]

Are you dosing anything yet? It seems like you are not. Most reefers daily dose for calcium, alkalinity, and to a lesser extent, magnesium My experience is that alkalinity depletes faster than calcium, so my daily dose for alkalinity is higher. That seems consistent with what you are seeing. KH is going down and Ca is not. This also depends on the coral in your tank too. A lot of coral growing fast consumes more from the water so your dosing needs are higher.

I had been using Brightwell's part A and B. Brightwell's part A has some Mg in it so I have rarely dosed Mg. Other brands are different. Red Sea has Mg in a separate solution. I just switched to the Tropic Marin's Balling method which adds a fourth part containing salt free trace elements. I recommend you searching R2R more on dosing information to get to a system that works for you. Anyone have any good links?

Sorry for the long answer. The short answer is dose for Alk and Mg as others have mentioned. I would add that you can use your measurements to calculate a daily dose rate, depending on what brand solution you have, and start using that, with a little extra, to bring the levels up to your starting point