Do you buffer your topoff?

[REEF-DADDY]

<a href=showthread.php?s=&postid=8364207#post8364207 target=_blank>Originally posted</a> by 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?



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.

Try it your way, at the end of the day the bucket supplemented with buffer(kalk in my case) will have a higher PH.

RO water won't bring PH down but kalk water will certainly bring it up

 

[LobsterOfJustice]

But I dont want to raise my pH, I want to maintain it.

I topoff with straight RODI, use a CaRx for calcium/alk. Double chamber reactor so I have observed no pH lowering effect.

 

[Mike O'Brien]

The ph of the pure water just doesn't matter at all, that's the point, it's just CO2 from the air that's bringing it down. As soon as it drip's into the tank it's matching the tank and there was no loss of alkalinity by doing so and no drop in ph.

The fact is if you buffer you're topoff water with an alkalinity building buffer you're going to raise the alkalinity too much. Kalk is different, but believe it or not not everybody want's to use it.

You could just keep some crushed coral in the reservoir, that would buffer all the incoming pure water before it was added to the tank. But again, there is no effect on the tank, so why bother.

 

[jjjimmy]

My only thought in this discussion is that if you are using an auto top off system, you are adding small amounts of top off water 24/7. Adding top off in small amounts in this way is going to have a minimal effect if any. I could possibly see where there would be a small Ph spike if you were adding all of the top off water at the same time at the end of your day.

Using Kalk or not is irrelevant if your Ph is stable and you are topping off in small amounts over the period of a day.

 

[Mike O'Brien]

<a href=showthread.php?s=&postid=8366473#post8366473 target=_blank>Originally posted</a> by jjjimmy
Using Kalk or not is irrelevant if your Ph is stable and you are topping off in small amounts over the period of a day.

What's irrelevent is the ph of the pure water.

 

[onehundred20]

does the PH drop as water evaporates? would that be the reason to add a ph bufferning component?

i dont get as technical about this stuff as some, but it is interesting to think about....my question is your calcium/alk salt whatever isnt evaporting its just the water, so why would you add more alk/cal and ph buffer. isnt that like adding salt with your top off water.

 

[Donw]

Ive heard alot of folks say you need to blow of the co2, this is really not the case with di. Di resin absorbs most if not all the co2 anyways.

Don

 

[Mike O'Brien]

Anthony is not talking about limewater.

By "buffering" the Ro/Di water, I mean "remineralize" it to give it some hardness and stability (using common seabuffer... carbonates and bicarb mostly).

The question is if you need to buffer the makeup and topoff water.

The pure water is "hungry" highly reactive and ready for chemical reaction's. It doesn't want to be pure, the carbon dioxide in the air alone is responsible for the low ph reading. Ph is effected by alkalinity and CO2 only and the ammount of CO2 cannot effect alkalinity. So barring the effect's of the CO2 in the room pure water can have no effect on the ph of the tank.