Ph buffer for top off water?

[Ty1e]

this is most likely a dumb question, but do you guys use a ph buffer added to your topoff water? i've started check the Ph in my Ro/di unit and it's to low to put in my 30gal with out changeing my tank ph.

[Shooter7]

Have you tested your tank pH before and after adding topoff water and letting it mix in with the tank. To me, you're simply replacing what was lost, so there should not be a real appreciable change in your normal values. I don't even see any real fluctuations in my 10g while adding topoff.

To answer your question, no, I don't add any buffer to anything.

[der_wille_zur_macht]

Technically, 100% pure RO/DI water doesn't have a measurable pH, and if you are getting a result, it will be extremely unstable and essentially meaningless. Since pH is essentially a ratio, it looses meaning in our case when the two things we're comparing the ratio of are present in extremely small amounts.

To give a more direct answer, you need to be concerned ONLY with the pH of your display, not the pH of your topoff water. The topoff is there to balance evaporation, which is 100% H20 - so on it's own, that is all you need it to be.

However, topoff water can be a convenient vehicle for delivering tools to modify certain water parameters in the display tank, including pH, alkalinity, and calcium. The most popular way to raise all three is using kalk powder in the topoff, but you can dose any chemical designed to modify those parameters into the topoff before adding it to the tank.

Again, the important thought is that you want to monitor/control the parameters of the display tank, not the topoff water.

[Ty1e]

ok thanks, i wasn't sure i needed to do anything to the topoff water. kalk power, is that better then dose just Cal and Kh and a Ph buffer on there own. because i have no way of adjusting the ph in anyway(don't have a buffer) so would kalk powered be a good staple to have around and dose?

[WaterKeeper]

I totally agree with that Der Wille.

I've always wondered if Der Wille's real name is Will Powers.

If both Ca and Alkalinity levels are low in the tank them KW is the answer.

[Shooter7]

If you need to actually dose something to keep your levels up, kalk can be good. Do you test your Ca, alk, and pH and find a need to dose these things?

[der_wille_zur_macht]

Originally posted by WaterKeeper
I totally agree with that Der Wille.

I've always wondered if Der Wille's real name is Will Powers.

If both Ca and Alkalinity levels are low in the tank them KW is the answer.

I agree - kalkwasser is an easy way to maintain calcium, alkalinity, and pH all at the same time. I wouldn't use it alone if you need large adjustments or if you have a very heavy coral load, but it can be a great regular maintenance tool.

Like Shooter mentioned, test all three of those parameters and make sure they are in the right proportions to eachother. If one or two of the three are waaaaaay out of whack but the other(s) are fine, don't use kalk - it will raise all three. In that case, dose something specific to the parameter you need to adjust, then use kalk to maintain once things are relatively correct.

If you have very little coral load on your system, you might find that you can use plain RO water for most of your topoff, and do a batch of kalk once a week or less. At any rate, read up on the stuff - it can be somewhat dangerous (as any chemical can) if not used properly - you want to be sure you're mixing in the right proportions, and adding it slowly rather than just dumping a large batch into your system.

[Ty1e]

ok, my tank water has been pretty stable (Cal 425-450,Kh 9-11, ph 8.2, Mag has been high 2.000ppm i think its because the seachem Cal rise stuff i have has mag and strom in it, so when i try to raise Cal i'm adding more of the other two aswell. and right now i just have large frags and one sps acropora colony.
( and a clam) so i don't think there takeing that much from the water in the way of Cal or mag etc.

[Ty1e]

here's a tank pic, it's a new tank(7-8 months old).

[der_wille_zur_macht]

Seems like things are OK in your tank as-is. You mentioned that you were dosing a calcium supplement - given your low coral/clam load, you could probably get away with replacing any calcium and alkalinity supplementation with kalk, and save a bunch of money in the process.

[seapug]

The advice I've read on wetwebmedia.com says it's a good idea to buffer your topoff water with baking soda to minimize alkalinity/ph affects.

[Shooter7]

My response to that would be that I have done topoff water to my system in two ways over the time I've had it running. In the early days I just dumped a bunch of RO/DI water into the sump to make up for the evap of the day - so there you have about 2 gallons or so all going in at the same time (about a 150g system) and a pint or so going into my 10g at one time. I have a pH probe in my large system and test the 10g. In neither was there even a small bump in the pH. I now have an ATO unit on my large system, but still dump water into the 10g, and there continues to be no alteration in my pH attributable to the topoff water.

So, if I have zero pH/alk effects from adding topoff, how can I "minimize" the effects? However, on the converse side of that, if I go messing around with adding stuff to my topoff water, and my topoff needs vary from day to day, what is that going to do to my display tank chemistry when it starts getting varying doses of buffer coming in with the topoff?

[Ty1e]

good point, i think i'll get some kalk and leave my topoff water alone.

[Ty1e]

what's the best kalk to get?

[WaterKeeper]

Well, Mississippi Lime is probably the best and purist but it is only sold in bulk. Far easier to obtain are Mrs. wages or Ball's Pickling Lime, which you can pick up in the canning section of most grocery stores.

Seapug,

Neither pH or Alkalinity should be an issue when you use RO/DI for topoff. The water adjusts to the conditions in the tank almost instantly so there is only the slightest drop in alkalinity during topoff. Of course, you can add baking soda but the steady build-up of sodium when using sodium bicarbonate is, in my opinion, more of a concern than a miniscule drop in total alkalinity using unbuffered water.

[seapug]

I actually don't buffer my topoff water, either. I was just pointing out what the "experts" have had to say about it.

[WaterKeeper]

Originally posted by seapug
I was just pointing out what the "experts" have had to say about it.

Me too but there is never one around when you need one.

[Ty1e]

is there i directions on how much lime water to add to my tank for what results?

[Ty1e]

so is lime water from the store better then buying kalk powder from the LFS?

[Shooter7]

You need to do some daily tests of Ca and alk to see what your tank use is. I believe der-wille's post previously alluded to this regarding tank usage. If you aren't seeing appreciable drops in your test results, then your tank isn't using much and your need to drip kalk is not very urgent and could possibly be controlled simply with water changes rather than adding something. All about the tank's usage. The results of using kalk is simply maintaining levels. You get the levels where they are supposed to be, then work with your kalk drip to see how much you need daily to maintain levels.

[der_wille_zur_macht]

Originally posted by seapug
I actually don't buffer my topoff water, either. I was just pointing out what the "experts" have had to say about it.

Again, in the end, the only thing that's important is the parameters of your tank itself. Adjusting your topoff to XYZ alkalinity is only meaningful if that's what it takes to get your display tank correct.

so is lime water from the store better then buying kalk powder from the LFS?

Lime from the grocery store is better because it's waaaaaaaay waaaaaaaaaaaaay cheaper. It's pretty much the same stuff. Generally, you want to saturate the solution, i.e. put as much in as the water can dissolve. that's somewhere around a tablespoon or two per gallon of RO water, depending on who you ask. Adding a bit more than required is OK, because then you'll be sure to hit saturation. Put the water in the container, add the powder, and shake/stir like mad. When doing kalk manually, I like to use a gallon milk jug - it's a good size and you can cap it to shake it vigorously. A gallon might be too much or too little depending on your tank, of course - the last time I dosed kalk manually by the gallon was on a 55g tank with a moderate coral population, and I'd do it twice or three times a week. Again, YMMV.

After mixing, let it sit for 20 minutes or so to settle.

Once it's mixed up, you need to gently introduce it to the aquarium. The best way to do that is to slowly drip it. You can buy one of the adjustable IV drip lines, or make a poor man's adjustable line. The simplest way to do that is to use a length of air hose, and restrict it to control the drip rate. You can simply tie a loose knot in it, or use a clothespin to partially close it off. Either way, you're looking for a drip a second or so - the idea is to spread the dosing out over a few hours, plus or minus. Do this at night, after the lights have gone off, to get the most benefit from the pH boost the kalk will give you.

Regardless of your delivery method, you'll find that there is some pasty gunk in the bottom of your container. DO NOT introduce that into the aquarium! If you are using a hose to drip it, make sure the hose can't suck that gunk up.

[Ty1e]

thanks der, is there a page you can direct me to for more info on manually doseing lime water- like how too's and why not's.

[WaterKeeper]

Here is one design by Agu Lukk A Simple Kalk Dripper.

The important thing is to make sure you only use the clear supernatant in the tank itself. Calcium Hydroxide, KW, has a solubility of around 1.85 grams per liter. That is not very soluble but if the tank were to get that much to dissolve the pH would rise to about 12.5 and you would have some very unhappy fish and inverts. You mix the powder into the water and let it completely settle, usually about an hour or two before using it. Then siphon off the clear saturated lime solution without removing the solids.

Here is another DIY dripper. This one includes a KW reactor too Dripper with Reactor.

Search around our DIY forum for other threads showing how to build a homemade reactor.

[der_wille_zur_macht]

Listen to WK's advice carefully. Word has it he was in this hobby when I was still in diapers!

[WaterKeeper]

Diapers? Before you were a twinkle in your mothers eye.