Need confirmation I'm doing this okay :)

[PufferMe!]

I just joined, because I've got a GSP (under 2 inches) and want to make sure I'm adding Instant Ocean correctly. He was in freshwater at the LFS. I started with 1/4 cup of Instant Ocean in my 27 gal tank (when I got him about 2 weeks ago). I've since done 2 WC of 30-40% adding 2 T. the first WC and 3 Tablespoons today with WC. That is a small increment, but when I tested the water today with my refractometer, I'm getting a reading I can barely detect, at about 1.004. Does that seem about right? Should I increase salinity more, less each week? I'm I on the right track?

Changing a tank over to brackish, is not easy I need someone to tell me how much to add each time, if I'm taking out 12-13 gallons each week.

Anyone want to tell me what to do? Ugh! Thanks for any help! BTW, he seems very healthy and happy. Eating well. He sometimes, goes up and down the glass, so I'm guessing he could be "happier"

[PufferMe!]

Hey, never mind I found the formula on this site, from Dad0.. something. Don't remember the full name.

Thanks so much for posting that! Very helpful

[Pufferpunk]

Cool, I was just gonna go find it for you.

[PufferMe!]

Thanks for the welcome. The only thing I realized, is the formula doesn't take into account how much water you take out. Here's my problem. I don't have enough of a container to mix all the water together, that I'm putting back in. I have 2, 5 gal buckets. If I have a water salinity of 1.004 (in the tank) and want 1.006, and I have each bucket of clean water I want to add to the tank, read 1.008, I'm not sure if I would get a SG of 1.006 when I'm done? Or would I? Does that make sense? I don't have a powerhead to mix, and the package says you don't need to do that, if you stir good. Is it adequate enough to just stir? For how long? Is there something I need to know about mixing Instant Ocean before I just assume the salinity reading I'm getting is accurate?

Thanks!

[J-P]

to keep the math simple, do 10 gallon changes. And assume it is a 20 gal tank. When you think you're at the 1.006 ~ 1.008 mark, take the tank readings more carefully, and ease off until you're above 1.012. Then back on schedule and start to ease off again above 1.020 and keep reading that tank.

In this situation less and longer is better then more and faster.

[PufferMe!]

Okay - thanks!

[RTR]

+1 to J-P's comments.

FYI - Specific gravity 1.008 - 1.012+ is the transition range for the bacterial nitrification types. Below that range yhe freshwater types predominate. Above that range, the saltwater bacterial species predominate. In the transition, slow is highly beneficial so that you do not kill of the FW forms before the SW forms have grow to sufficient numbers to carry the load.

Specific gravity 1.018 - 1.020 is the top end on brackish water for most folks. Specific gravity of 1.021-1.025+ is marine rather than brackish water. .SW is the levels where skimmers work well amd live rock establishes well.

HTH

[PufferMe!]

I appreciate that info