Water for Evaporation

D

Drill Sergeant

Member
Hello All

What type of water do you all use to replenish for evaporation? I've been using 1 gallon of distilled water a day for the last 2 weeks as my tank is still in its cycling stage, and now one of the LFS's tells me that I should add spring water.

Whats your take on this

DS
 
Woodstock

Woodstock

The Wand Geek was here. ;)
RS STAFF
Distilled water is better than spring water.

I use tap water for my top offs.... yeah, I need a water purifier!
 
M

Montanareefer

Has been struck by the ban stick
Distilled water is the better bet but not really sure how really pure that water is but will work fine.

Having a RO/DI unit is the way to go as I am finding out.:)
 
BoomerD

BoomerD

Well-Known Member
I have a good R.O./DI unit and lose about 3 - 4 gallons per day to evaporation from my 90 and 40.
 
nigle

nigle

Member
Oi!

Remember that if you use RO/DI water for top off, you need to have it 'aireated'[sp] well you need to let it bubble for at least a day before you use it. The RO/DI water is 'clean' and the O2 in it is also gone. Also you need to check the buffering, since the RO/DI removed everything, it needs to be buffered too.

Cheers!
nigle
!~!
 
Dingo

Dingo

Member
Don't use spring water. Just because it came from a well doesn't mean it's not chock full of dissolved things that you don't want in your tank.
 
wooddood

wooddood

the wood dude
i use ro/di water for all my top offs and have never airiated it before using it and have never heard this before. am i missing something?:confused:
 
jks1

jks1

Member
Dave, I aerate the water when I make a bunch for a water change (usually 40g at a time). I try and let the mixed saltwater sit for a week with a strong PH in the can.

But for top-off I run mine plumbed directly into the tank.
 
Dingo

Dingo

Member
Originally posted by wooddood
i use ro/di water for all my top offs and have never airiated it before using it and have never heard this before. am i missing something?:confused:
Click to expand...

I doubt that the RO process can de-gas water. The holes in the membrane have to be large enough for a water molecule to fit through, which is larger than an oxygen molecule (I think).

Even if the water was completely gas-free, adding a gallon at a time for topoff to a 120 gallon tank would result in less than a 1% drop in gas/volume in your tank, and in reality, probably less than that.

I wouldn't worry unless you were doing a major water change. Even then, I wouldn't sweat too hard.
 
Witfull

Witfull

Well-Known Member
by simply pouring it into a container and then pouring it into the tank will help airate it. also if you are putting it into the overflow or sump that will almost immediately mix air as it passes through the pump. for top off concerns, this is not a concern.

when i do my top off, i use a 1 gal water jug and i add a smidge of calcium and shake.
 
H

Hooked

Member
Nigle wrote

Remember that if you use RO/DI water for top off, you need to have it 'aireated'[sp] well you need to let it bubble for at least a day before you use it. The RO/DI water is 'clean' and the O2 in it is also gone. Also you need to check the buffering, since the RO/DI removed everything, it needs to be buffered too.
Click to expand...

You know that's interesting (about the buffering). Just last night I checked the pH of my RO/DI water and it's almost 10. I'd never thought about the buffering before and I'm not really going to worry about as it's such a small amount of water.
 
Dingo

Dingo

Member
Hooked, PH measurments don't work right with RO/DI water. There are not enough H+ and OH- ions in the water to get a reliable reading. Even though the water is reading very basic, it is not really.
 
Dingo

Dingo

Member
Sorry. You need enough acid or base in the water for the PH test chemicals to react with and change color. Your water is so pure that there is no acid or base to react with, so you can't believe the color readings. You would have the same problems with an electronic PH probe.

Adding the smallest amount of buffer to the water would allow you to read the PH properly, but it isn't really an issue because adding the neutral water to your salt tank won't influence the PH one way or the other.
 
H

Hooked

Member
Okay, that I got! You have to give me a break as I was a finance major--never took a chemistry class, but thanks to these little lessons you guys give, I'm learning! Thanks!
 
BoomerD

BoomerD

Well-Known Member
I swapped a couple of e-mails with Dr. Holmes-Farley on this subject, and he says no buffering is needed. The chemicals/minerals in the tank that provide the salinity, hardness, & such don't evaporate out, and stay in the tank. R.O. water will not drop your pH. when you do top-off's. Granted, if you have a 50 gallon tank, and are topping off 10 gallons per day, you will see a big change in pH, salint and everything else, because it's such a large amount, but as long as you do small amounts, (less than 5%) it should be no problem.
Keep in mind MojoReef's bucket of marbles analogy. If you add water that has been buffered for alk or cal., it will force a change in the existing water. Whether it bumps the salinity up, or causes a precipitation of another element, it WILL change something...
 
H

Hooked

Member
jks1, I have a Pinpoint and that's how I came up with that reading. I was just standing there with a bucket of fresh RO looking at the meter and thought " I wonder what the pH of RO water is" plop, "holy moley" :D

Well, I might have said something else ;)
 
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