Do I add buffer to my fresh water ?

[magnum629c]

When I add water to top off my tank do I need to add buffer to my ro/di water ? Some people been telling me to add buffer and others say just add the water to top it off. I just dont no if adding water thats 7.0 to a tanks thats 8.3 would hurt my PH in the tank thanks!

[Sk8r]

Many people add both buffer and calcium by hand to the sump. Personally, I add buffer to the topoff water. If you can accurately determine how much buffer your tank uses daily, then 2) establish how much topoff water your tank draws daily, [evaporation rate, in other words] then you can calculate how much buffer you could add to your topoff reservoir.

As an example: my tank uses 2 tsp buffer daily, and evaporates one gallon daily. My topoff reservoir holds 5 gallons. So my reservoir is good for five days, and if I add ten tsp of buffer to that water, it's done for that five days and all I have to add to the sump is the calcium.

This is particularly useful because you cannot add buffer and calcium at the same time: they cause each other to precipitate out as a white cloud, and do no good to the tank. By having it in the topoff water, you get to add the other element with no likehood of a chemical fallout, and do it at one time per day instead of having to do one in the morning and one, say, in the evening. So it's more than a few spoonfuls of effort this practice is saving you.

You must, however, have a stable demand and a stable evaporation rate for this to work well.

[bertoni]

[welcome]

A buffer should be added as part of a calcium-alkalinity supplementation scheme. I add limewater to my topoff water, and drip it into the tank, since that supplies both calcium and alkalinity in the correct ratio.

As Sk8r suggests, it's possible to add just the alkalinity supplement part to the topoff water, although I'd suggest using a 2-part like B-Ionic instead, since they are less error prone.

This article covers a lot of choices:

http://www.advancedaquarist.com/issues/feb2003/chem.htm

There's a recipe for a DIY 2-part, if you want to save some money.

[magnum629c]

ok Thanks guys ill try that!

[Sk8r]

Bertoni, that's the clearest explanation of kalkwasser I ever ran into. Merci buckets!

[BigJPDC]

hello Bertoni. Not sure if this should go in the Randy forum, but my t-o reservoir holds about 9 gallons, and lasts me about a week. I also buffer for dkh and calcium daily into the sump, depending on my readings.

Are you saying I could calculate the amount of buffer and calcium and put that in my t-o? Would the checmicals stay in suspension that long, i.e. a week?

jp

[bertoni]

No, you can't combine alkalinity buffers and calcium supplements in the topoff container like that. Only limewater will work there. Well, calcium acetate, as well, but that's fairly expensive.

[BigJPDC]

what a noob I am - sk8r answered my questions and I must have skipped his post. I know that you can't mix calcium and buffer, tripped over my own words there. I will have to log my evaporation rates and see about this.

Sk8r - does your t-o reservoir empty itself completely? The reason I am asking is that the mj1200 I am using as a t-o pump can't possibly get the last gallon or so out, so I replace the water when it gets near that point, roughly 5-6 days. So if I added five days' worth of buffer but all the water wasn't gone after five days when I refilled, wouldn't I be creating a super concentration of buffer in what is remaining?

If the proper thing to do is empty and rinse the container before refilling, that is probably more work than adding buffer each day.

Thank you, this has been killing me for a little while now and I appreciate your input!
jp

[Sk8r]

You have to allow for that extra water: I actually have a 7g reservoir, one g always stays behind, and I mix for 5, so it's worked out. But periodically I think you should flush that tank just to catch any precip and get it out again.

PS: DON"T neglect to puncture the line near the point it leaves the bucket, or you'll risk a siphoning effect that can start emptying your sump! Took me finding this out the hard way.

[BigJPDC]

Got ya. I have the return line jetting above the waterline, so no chance for a siphon.


Calculating the amount of buffer to add the ato is becoming quite complicated. And not only do you throw things out of whack by adding more buffer, but also more fresh water.
A solution as I see it, is to gather statistics on the amount of water the ato adds in some large amount of time near its capacity. Now you have your days\buffer\gallons ratio. The trick here is that you will only mix up a batch of buffered water using this ratio, thereby always refilling the reservoir with the same concentration of buffer, regardless of how much you actually add.

The only danger here is in the case where a significantly greater amount of to is added, because of maintenance or something, and for that period more buffer is added, hence using a full reservoir as the initial unit of measurement, and a greater time frame. I would add a week's worth of buffer to a week's worth of water, and at the end of the week both would have replenished the system.

I could always just pour three capfuls in the sump each night before I go to bed . . .

jp

[Sk8r]

Grin. This is where, after you've bent your brain with calculations, a refractometer is your friend, because it's not just the buffer, it's the salinity. A topoff accident is very frequent during the learning curve. Just remember to correct everything slowly, using the t/o that got you into trouble: too much freshwater? Add salt to the t/o. Too buffered in the main tank? Don't buffer for a bucket or so. One thing about buffering: it's not the most critically must-be-accurate operation, not compared to, say, salt. Anything between 8.3 to 11 in the main tank is acceptable, but not necessarily to your preference. Remember that whatever you do with 5g of buffered water is being applied to a 65 and 20g system, so it's not going to be disasterous even if you goof once. The very first time I set up my topoff, it was when I was going out of town. I knew it tended to let the hose slip, I didn't have a clamp, and right before I left town I got into that bucket and made sure the hose was secure. When I came back five days later, salinity was high---and not one drop of topoff had been used. Seems I'd forgotten to plug it back in after that last-moment inspection.

Didn't lose anything, but I certainly felt stupid.

Everyone who starts with one of these systems goofs sooner or later unless you maintain an astronaut's checklist of procedures and stick to it. Just try to slow down and think it through.

That's a very impressive bit of plumbing you've got going there. WIsh mine was that neat. My own is much more humble, and a bit crankier, I fear.

[BigJPDC]

=) thanks sk8 - it's really just some pvc parts holding the float switches and 1/4" airline tubing shoved through more parts, so no actual plumbing. You can see the return line poking out. I just wanted the wires and especially the 9v battery packed away in case of a flood.

I think I will drill my next sump for the ATO though. Thank you for the good advice here, the checmistry forum has taught me a lot lately.

jp