Do you buffer your topoff?

[Lobster]

I came across this thread where Anthony Calfo is explaining how you should never use raw RO/DI water without first aerating and buffering it:

Originally posted by Anthony Calfo
If you use DI or RO water... be sure to aerate overnight and then buffer before salting. Prefiltering the water from Go with carbon and/or polyfilters is not a terrible idea either.

Aerating I can see, since it would drive off CO2, but buffering? I use instant ocean, and my alkalinity after mixing is already much higher than I'd like. What's he talking about? And what would carbon do on freshly mixed saltwater?

Originally posted by Anthony Calfo
By "buffering" the Ro/Di water, I mean "remineralize" it to give it some hardness and stability (using common seabuffer... carbonates and bicarb mostly). Please... NEVER use raw RO/DI water. It is acidic and unstable and at best a burden on your tank's pH and alkalinity. It could be worse and is a very bad habit nonetheless.

Before buffering though, its important to aerate such water overnight to raise the pH temporarily (off-gassing carbonic acid).

Does anyone buffer their topoff in this manner? I always figured that evaporation would be freshwater, and the carbonate is left behind in the system. Is topping off with plain RO/DI water bad?

 

[Mike O'Brien]

Nonsence

 

[theatrus]

I topoff with RO+DI run through a kalk reactor... so in effect I'm buffering it. But I need the kalk + ca reactor to keep my carbonate levels steady.

 

[neyugn0w01]

Keep it Simple is the best advice I can tell you. Don't believe all the hoopla going on in this hobby.

 

[REEF-DADDY]

Why would'nt you think adding water with a very low ph would not effect tank PH in some way?

 

[Mike O'Brien]

because it's not low like people think. Pure water evaporates, we put pure water back in. It may read a low ph, but it's not acidic like said. There is nothing in the pure water to resist or cause ph change, so when you add it to the tank there is no effect at all.

 

[dvanacker]

I had this discussion on two forums....as well as here in the chemistry forum..... Randy agrees that adding straight RO/DI water for top off is fine and will not negaively effect pH.

 

[dvanacker]

I'll add that I do it and my pH is fine.

 

[Stoney Mahony]

Mee too, and no probs here.

 

[CeeGee]

I add straight RO/DI and I never see it effect my pH whatsoever.

 

[Mike O'Brien]

I think people just confuse hungry water with acidic water.

 

[db_triggerfish]

^

 

[Corn]

Kalk all the way and if needed Mag but not together

 

[NuclearReefs]

I mainly top off with Kalk,, If not I add DKH buffer to the water,, I dont think plain RO DI will drop PH ,, but if its below my levels its effecting it.. period .. Id rather it be a little high that 7.0

Nathan

 

[Lobster]

<a href=showthread.php?s=&postid=8362219#post8362219 target=_blank>Originally posted</a> by NuclearReefs
I mainly top off with Kalk,, If not I add DKH buffer to the water,, I dont think plain RO DI will drop PH ,, but if its below my levels its effecting it.. period .. Id rather it be a little high that 7.0

Hmm... how is it effecting it? One gallon of fresh water evaporates from your tank, you replace it with one gallon of fresh water. There's no significant net loss/gain. By replacing with kalk, you are supplementing carbonate that is being used by tank inhabitants, not making up for evaporated carbonate.

 

[NuclearReefs]

so the PH of the water that evaporates is 7.0 Lobster ???

 

[REEF-DADDY]

I guess I am over simplifying things but why would we add water back into the tank in the 7.0 range, when we could be adding water in the 9.0-9.5 range. Try this:

Take 2 5 gallon buckets of tank water.
Test the PH of each bucket
Add ½ gallon of pure RO water to one
Add ½ gallon of buffered water to the other.
Test the PH.

 

[naka]

<a href=showthread.php?s=&postid=8363928#post8363928 target=_blank>Originally posted</a> by REEF-DADDY
I guess I am over simplifying things but why would we add water back into the tank in the 7.0 range, when we could be adding water in the 9.0-9.5 range. Try this:

Take 2 5 gallon buckets of tank water.
Test the PH of each bucket
Add ½ gallon of pure RO water to one
Add ½ gallon of buffered water to the other.
Test the PH.

I couldn't agree w/ you more Steve.

I top off using Spectrapure LM3 to Kalk rx only at night to keep my PH above 8.


James

 

[Lobster]

<a href=showthread.php?s=&postid=8362432#post8362432 target=_blank>Originally posted</a> by NuclearReefs
so the PH of the water that evaporates is 7.0 Lobster ???

Thats what I'm wondering. Think of it like this... if you put a tablespoon of tank water in a dish and let it evaporate completely, wont there be salt, carbonate, and other minerals left in the dish as precipitate?

<a href=showthread.php?s=&postid=8363928#post8363928 target=_blank>Originally posted</a> by REEF-DADDY
I guess I am over simplifying things but why would we add water back into the tank in the 7.0 range, when we could be adding water in the 9.0-9.5 range. Try this:

Take 2 5 gallon buckets of tank water.
Test the PH of each bucket
Add ½ gallon of pure RO water to one
Add ½ gallon of buffered water to the other.
Test the PH.

But that is dillution. For your example to be the same as what we are talking about, you would have to take two 5-gallon buckets of tank water, let ½ gallon evaporate from each, then add back ½ gallon of RO/buffered water and test pH.

The question is, does pure water evaporate or does buffer also leave with the evaporated water.

Not that any of this matters. If Randy says its ok, Im sure it is. I just thought it was an interesting discussion.

 

[manderx]

i've read calfo's thoughts on this a few times. he simply doesn't understand pH/buffering. and whenever you point him to a randy thread that clearly proves him wrong, he just says 'i just scanned it because i didn't have time to read the whole thread but we are saying about the same thing'.

regardless of all that though, who in the sps forum wouldn't want to dose 100% of their topoff as kalk anyway? not to 'buffer' or 'remineralize' it to keep it from bringing your pH down but as a vector to supplement calcium/alk.