Math Wizz Needed

[ShadowBass]

And then throw the 45 gal taken in to the opposite tank it came from......





Edit: lol It's all good. I am not typing that clear either. The only other way is to swap 10 gallons at a time till the cows come home and the mix will also be 50/50 however draining a larger volume insures that at least that amount of original water was properly mixed.....

Yeah I agree with you, I somehow COMPLETELY misconstrued the original question and then missed a major component, lol.

It's a good thing nothing important relies on my math skills

They're really not that bad if my reading comprehension doesn't fail.

 

[Onion01]

My brain just died

 

[MrGuyPerson]

The thing to remember is that every subsequent exchange lowers the ratio of introduced tank water to old tank water. This means that each bucket will contain less and less of the water you're trying to add to the other tank. For example, after one water exchange, the 85g tank will be 10g from the 100 g tank and 75 from the 85. The 100 will be 10/90. The next 10g water change from the 85 will then be 8.8g from the 85 and 1.2 from the 100. The water from the 100 would be 9/1. The net total for water in each tank would then be 17.8g/67.2g, and 17.8g/82.2. This goes on and on and it becomes almost meaningless to exchange water as they get closer and closer to 50%. If you were to do 11 of these exchanges, the 85g would be almost exactly 50% water from the 100, and the 100 would be a little under 43% water from the 85. I stopped working on it soon after this as it gets pretty pointless. Once the ratios are close 50%, the net exchange of water between tanks is almost negligible.

 

[Bderick67]

Sorry to confuse everyone i though I had made it clear, note the whats highlighted in red below. Anyhow looks as if MrGuyPerson has answered it. I actually did this yesterday, to move my discus from the 85g to the 120g planted tank. I exchanged 80 gallons of water over 2 hours to bring the pH and nitrates equal in both tanks, 'course I still drip acclimated them for an hour too.

Here's what's invloved,

85 gallon tank full....so 85 gallons of water
120 gallon tank full....110gallons of water because of subtrate, decor.
4 5gallon buckets...I know at what point they actually hold 5 gallons

Start by removing 10 gallons of water from 120g tank

So I now have 85 gallons of water and 100 gallons of water.

By exchanging 10 gallons of water at a time, how much water would I need to exchange between tanks to make the water mixture equal in both tanks?

 

[ShadowBass]

Nah, I think I confused everyone more than you.
I was thinking you meant water volume rather than the compounds IN the water. I should have known since the former makes no sense for someone to ask

 

[Bderick67]

So you need to take 7.5g out of the 120g tank and put it in the 85g tank.

100 gallons - 7.5 gallons = 92.5 gallons
85 gallons + 7.5 gallons = 92.5 gallons

Now both tanks are equal.

Well now if the wife asks "why is the floor all wet?"

I can just tell her that ShadowBass told me to put 92 gallons of water in my 85 gallon tank.

 

[ShadowBass]

Well now if the wife asks "why is the floor all wet?"

I can just tell her that ShadowBass told me to put 92 gallons of water in my 85 gallon tank.

Well you know, 7 gallons on the floor isn't THAT bad....

I try not to use the python when I'm distracted anymore though...

 

[jus1time]

make both tanks 85 gals then exchange equal amts. sounds pretty easy to me.

 

[Bderick67]

make both tanks 85 gals then exchange equal amts. sounds pretty easy to me.

Would've been real easy to do that way, if I didn't have to consider the acclimation of my discus.