Different Water measurements

[extoker]

Hi. Last week or sometime someone replied to a post with the formulas for water changes to arrive at different specific gravities and various other measurements. I forgot to write them down or subscribe to the thread. Does anybody recall the thread please?
Thanks
Tim

[disc1]

C1V1 = C2V2

Concentration times volume at the beginning equals concentration times volume at the end.

So if you have 37ppt and you want 35ppt in 100 gallons.

37 * x = 35 * 100

x = 94.6

So you'd keep 94.6 gallons and replace 5.4 gallons with fresh RO.

[extoker]

Thanks! But there were several other equations in the post for different things, but I don't recall what they were for the life of me.

[Randy Holmes-Farley]

I don't recall the exact thread. If you tell us what you want to figure out, we can provide an equation for just about anything. :)

[extoker]

Thanks Randy. The first thing I need to figure out is addressed by disc1. I already had this from the post the other day (been searching all day for the post but no luck). The other equations I wanted to keep just because they would come in handy on down the road, but I can't remember what the were.

I don't recall if it was a sticky or not (done and searched the stickies...), but do remember it was on page 4 of the reply (I know that's useless with the amount of post that occur each day)

[Randy Holmes-Farley]

Sorry, there's no such sticky in this forum. :)