Low alkalinity new tank

[ibrat82]

Hi guys

So now that I'm adding corral to my tank I've been checking all my parameters and it seems my alk is low for the salt I'm using. When I started the cycle I was using io reef crystals but after my cycle was done and I did a 60% water change with Red Sea coral pro. Both salts have high alk. I've tested each batch of salt and I'm getting 12 dkh. How is it that my tank has alk reading at 7.6 dkh??? There's no Corals in the tank? No corralkne algae growing. I also have ph around 7.8-8.0. I know the 2 are related.

I run a hose outside into my skimmer, run chaeto reactor. Have my mp40 near the surface of water to promote gas exchange.

What could cause my low alk?

 

[tkeracer619]

Alk will always drop, even in the container you mix the salt in.

No big deal if you aren't keeping coral but sicne you are you will want to test and dose to keep it stable.

I use baking soda to adjust alk. Typically I shoot for 9dkh, 420ca, 1260mg min.

 

[Uncle99]

I test and maintain magnisum first, then do Alk and calcium.
Mag is the buffer between the two, if magnisum is too low I get low reads on Alk....

 

[ibrat82]

Magnesium is 1350, cal 430, and all 7.5 as of today checked this morning.

Should I be dosing or using kalk? Again not sure what's depleting my alk as I don't have corals and my salt is testing at 12dkh alk.

Is this typical new tank issues?

 

[tkeracer619]

Typical, yes.

I wouldn't dose Kalk unless there is demand. Alk will naturally fall regardless of demand.

Use baking soda or soda ash to raise it and keep alk stable.

Once you have demand you can consider dosing kalkwasser.

Magnesium needs to be 3x or greater than calcium. So you are well within that range. Some people keep it much higher.

Also, 7.5dkh is not really that low. There is nothing to worry about here. Depending on salt mix that high alk after mixing is only temporary. I have had some salts go from 10 to 6dkh in just a few days. Also, when mixing salt, do not preheat the water. Salt mixes better into cool water.

 

[theaalex]

How much baking soda do you use for say a 100g tank? Do you just start out small like a teaspoon/day and test then go up from there?