How to buffer top off water?

eugene22_73

New member
This might seem like a simple question, but how do you buffer your RO top off water. Though I’ve been in the hobby for some time, this one simple question keeps coming to mind and so I though I would ask. I use ESV 2 part in my tank. (no kalkwasser).
 
if your using b-ionic theres no need to worry about buffering your RO top-off water. what exactly are your concerned about buffering? calc, alk, pH?
 
Your buffer has a dosing recommendation per day, right? Figure out how many days your topoff bucket lasts before refill...say, 5 days. So if it's lasting 5 days, and your dosing is 2 tsp a day, you buffer the topoff with 10 tsp, and your buffer water is going in at the right rate. Check this level periodically and don't let the tag end of water in your bucket nudge the buffer too high.
 
Buffering or adding anything to Ro/DI topoff water is unnecessary as nothing but pure water evaporates from the tank, and the tank water does not lose any of its buffering capacity from evaporation.
 
that's actually unture HowardW.

RO/DI water may be very pure, but it will usually have a very low ph and will cause problems if added directly to the tank unbuffered. It is important to bring the ph of the topoff back up to a workable range so it doesn't mess with the ph/alk of the tank when added.
 
<a href=showthread.php?s=&postid=8069332#post8069332 target=_blank>Originally posted</a> by xcreonx
that's actually unture HowardW.

RO/DI water may be very pure, but it will usually have a very low ph and will cause problems if added directly to the tank unbuffered. It is important to bring the ph of the topoff back up to a workable range so it doesn't mess with the ph/alk of the tank when added.

actually Howard is very correct :D. your tanks buffer capacity will buffer the RO water almost instantly. now if you add 10 gallons of RO to a 20 gallon tank will it buffer the water? no, because you have exceeded the tanks buffer capacity.
 
<a href=showthread.php?s=&postid=8068954#post8068954 target=_blank>Originally posted</a> by Sk8r
Your buffer has a dosing recommendation per day, right? Figure out how many days your topoff bucket lasts before refill...say, 5 days. So if it's lasting 5 days, and your dosing is 2 tsp a day, you buffer the topoff with 10 tsp, and your buffer water is going in at the right rate. Check this level periodically and don't let the tag end of water in your bucket nudge the buffer too high.
Not entirely accurate... :D
If you want to add buffer to your RO/DI do not follow the dosage directions from the manufacturer, they are calculated for an average tank and the usual deviation could be significant.
You need to determine your consumption first either by measurent or by trial and error, once you know use that as the amount to add.
By the way If using buffer other than Kalk you will be able to only maintain either Calcium, Alkalinity or Magnesium depending on the buffer but you can not mix buffers of different type in the same batch.
 
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<a href=showthread.php?s=&postid=8069141#post8069141 target=_blank>Originally posted</a> by HowardW
Buffering or adding anything to Ro/DI topoff water is unnecessary as nothing but pure water evaporates from the tank, and the tank water does not lose any of its buffering capacity from evaporation.
While it is true that only pure water evaporates from the tank, Calcium and Alkalinity gets consummed so buffering the top off might be ways not only to replace the evaporated water but also to add those ions consummed.
 
<a href=showthread.php?s=&postid=8069383#post8069383 target=_blank>Originally posted</a> by jdieck
While it is true that only pure water evaporates from the tank, Calcium and Alkalinity gets consummed so buffering the top off might be ways not only to replace the evaporated water but also to add those ions consummed.

which he is doing using the 2 part additive :D.
 
<a href=showthread.php?s=&postid=8069332#post8069332 target=_blank>Originally posted</a> by xcreonx
that's actually unture HowardW.

RO/DI water may be very pure, but it will usually have a very low ph and will cause problems if added directly to the tank unbuffered. It is important to bring the ph of the topoff back up to a workable range so it doesn't mess with the ph/alk of the tank when added.

Not entirely accurate... :D
While the PH of RO/DI water could be low it has not capability to affect the tank PH.
Because RO/DI water has been stripped of all buffers its capacity to maintain a certain PH is nill. It's PH changes as it absorbs CO2 from the surounding air much as the tank does. Because of the lack of buffering it will adjust to the tanks PH as soon as it is mixed with it.
 
<a href=showthread.php?s=&postid=8069396#post8069396 target=_blank>Originally posted</a> by Paintbug
which he is doing using the 2 part additive :D.
It of course could be one or the other or a combo of both :D

If Kalk mix top off volume matching the evaporation is not enough to maintain Calcium and Alkalinity then additional buffering will be required, here is were a two part can become handy.
 
JDieck, thank you, yes: my tank happens to be spot-on with the recommendation of dKh buffer, and it was bad advice on my part to rely totally on the manufacturer's per-gallon without individual figuring.

I've never been able to figure out Kalk. I know an overdose can be disasterous. I'd be delighted to use it if I could figure it.
 
<a href=showthread.php?s=&postid=8069801#post8069801 target=_blank>Originally posted</a> by Sk8r
I've never been able to figure out Kalk. I know an overdose can be disastrous. I'd be delighted to use it if I could figure it.

In reality is not as complicated:
1. Prepare the mix: Take 1 gall RO/DI or distilled water, add 2 teaspoons of Kalk powder, shake or mix vigorously and let settle.
2. Once settled drip the clear milky liquid into a high flow area of the sump or tank, the slower the drip the better.
3. Monitor PH, if it starts rising more than 0.2 slow down the dripping even more.

That is all there is to it.
Now having said that, the complications start when we try to determine how much volume to use and to tie that volume to the daily consumption but not even that is difficult (If you have the right teacher that is :D). Lets see:

A) Determine the volume to add:

Use the chemistry calculator to determine how much Alkalinity your buffer is adding to your tank and then how much Kalk volume you need to add the same alkalinity. To do this enter your system volume, Enter as actual alkalinity of 6 dKh (Any number will do, as we are interested in the increase.) Enter as desired alkalinity any number larger than 6 (say 7) Select your supplement and calculate. Take a look at the amount required. Is the amount required more or less than the amount you use? If it is more then change desired level to use 6.5 instead of 7 calculate and compare the amount again. Keep on changing the desired level until your calculated amount matches the amount you use every day. The difference between the desired amount and the number you have as actual (6 dKh) is your daily consumption.
Now that the consumption is already entered, select as supplement Saturated Limewater (Kalk) as the supplement. The calculator will tell you how much volume of Kalk you need to replace the amount of the buffer you are using.

Alternatively to this method which rely in the known amount of buffer you can actually measure your alkalinity consumption. To do this test for alkalinity. Wait 48 hours without adding any buffer and test again at 48 hours. Divide the difference by two and that is your daily consumption. Use the calculator to tell you how much volume of Kalk to use for that consumption. To do this enter your system volume, enter as actual alkalinity the value of your first test. In the desired alkalinity enter the value of your first test plus your consumption, select Limewater as the supplement and that's it. You get the required volume of Kalk to add every day to replace that consumption.

B) Determine if Kalk can be used to replace evaporation:

It will be very simple if your volume of evaporation matches your required volume of Kalk, if it does then that's it just add the Kalk instead of Top Off.
Now lets see what to do if it does not match:

1) Evaporation volume is more than the volume required of Kalk:
Simple... Add the volume of Kalk and add RO/DI top off volume equal to the evaporation less the volume of Kalk. If you have an auto top off just drip the required Kalk and the top off will automatically top off less RO/DI water.

IMO is more difficult to do but alternatively prepare a less than saturated solution of Kalk by adding less than two teaspoons per gallon. Determine by trial and error how much less Kalk to use until your volume of less than saturated lime matches your evaporation.

2) Evaporation volume is less than the volume required of Kalk:
Easy too, just add all the evaporation volume with Kalk. In this case because you are reducing the amount of Kalk needed your Calcium and Alkalinity will slowly decrease so you will need to manually add a two part additive to make up for the difference.

I hope this explanation helps to clarify the mysteries of Kalk addition :D
 
I heat a cup of RO water to about 150 degrees and add some baking soda and stir it. then let it sit and put an airstone in it untill its tank temp then add it to your tank or sump or top off water.

Note: only pour in the soloution not any of the sediment off of the bottom.
 
<a href=showthread.php?s=&postid=8070617#post8070617 target=_blank>Originally posted</a> by vanmo92
I heat a cup of RO water to about 150 degrees and add some baking soda and stir it. then let it sit and put an airstone in it untill its tank temp then add it to your tank or sump or top off water.

Note: only pour in the soloution not any of the sediment off of the bottom.
I do not think it is necessary unless you are trying to dissolve a huge amount of baking soda which I am sure will exceed an addition safe limit.
 
Thank you ever so much, JDieck. I'm going to sit down with a pencil and try to figure this out. Right now my evap rate for my 62 gal system is a very convenient 1 gallon a day, and if I can make this work through the autotopoff, it would make matters much easier. The only thing I need to assure is that I'm very, very careful with the autotopoff switch and plugin: not a situation for mistakes, for sure.
 
I have always just added pure RO/DI water back into the tank. I have a pH Monitor on my AC Jr. and have never noticed an effect on pH. I also dose b-ionic.
 
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