water change calcium/alk

[KLN]

Just mixed a new batch of Instant Ocean, and got Ca 380 and KH/Alk of 4.25. What are you folks seeing in a new batch of RO and Instant Ocean?

It seems I can interpret the Salifert Ca test plus or minus 10 ppm or so just the way I read the test.

[jackdp]

Those numbers seem about right for IO . Its usually low in Ca and not ionically balanced. The Alk is a little on the high side but fine. If you want to get it a little more balanced, try adding some Calcium Chloride like Kent turbo calcium. Bring the Ca up in the 420-450 range and the alk should fall a little evening things out. Also, what specific gravity are you mixing it to?

[KLN]

35 PPT, or 1.026 at 80 degrees.

Do my test results match yours for RO and Instant Ocean?

I figure about 1/2 tsp. of Turbo Calcium should do it. Right?

[jamal-188]

Originally Posted by KLN

35 PPT, or 1.26 at 80 degrees.

I figure about 1/2 tsp. of Turbo Calcium should do it. Right?

I would drop to 1.025. When you say 1/2tsp, how much water are you mixing this with? That stuff is pretty strong.

[KLN]

oops. 5 gallons.

[jackdp]

Its been a long time since I used IO and don't remember the exact results, but what you're seeing sounds in the ballpark. The half teaspoon is probably close, here is an online calculator for figuring the correct amount of CaCl2 to add... HTH

http://www.andy-hipkiss.co.uk/index.....uk/cacalc.htm

I would also drop the SG to 1.025 or even 1024. 1.026 isn't too high, its pretty much the high limit though.

Considering the smaller water volume, I would actually suggest ¼ tspn instead. It will allow the Ca to come up without a supersaturation possibley causing precip. You will most likely need to add about 3 of them several hours apart. ½ tspn of Turno Ca will only bring it up to about 425 ppm Ca depending on the Mg level.

Cheers
Steve