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How fast is a pH change detectable?

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sfsuphysics

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Just curious if I were to set up some drip system with kalkwasser, and had hooked up to some controller (ACjr, RK2, whatever) such that I could turn a solenoid on/off whenever it got to high would that be practical? I know those with calcium reactors do the opposite of this when pH is too low, but is that more of a safeguard net? Or is it something that it gets too low from a detectable stand point, the pH will eventually drop a few more tenths when the system circulates and equalizes to whatever spike from the effluent.
 
PH change is pretty quick. if the prob is close to the kalk drip, it would work well. On my 150, if Im adjusting my PH, which I have done with vinegar, it takes about 1 minute for the entire system to balance out.

Ive measured this by having the PH probe in th sump whee the water enters. I dosed vinegar near the return pump and it takes 1 minute for the vinegar to go through the system and back to the pump to change the PH reading.
 
It depends how much flow you have in your tank, my guess would be if you have more flow additives will be mixed thoroughly enough for your probe to detect assuming it is in your sump.

Kalk will maintain alkalinity and calcium to a certain degree so my opinion is it's more of a maintenance additive.

It will temporarily give you a ph boost. If you want to raise alk to a particular degree of hardness you can use buffer (whatever brand suits you) or baked baking soda if you're cheap like me.

Calcium reactors will drive ph down over time while it's on. This maybe a no-brainer but it's generally not a good idea to have it on 24/7.

My calcium reactor is tied to my lighting schedule so it only doses when the lights are on. The Nielson/kalk reactor is tied to my auto-topoff so it slowly doses over day and night.
 
[quote author=sfsuphysics link=topic=2586.msg26833#msg26833 date=1195144181]
Just curious if I were to set up some drip system with kalkwasser, and had hooked up to some controller (ACjr, RK2, whatever) such that I could turn a solenoid on/off whenever it got to high would that be practical?[/quote]

Controller, solenoid, pH probe is just more stuff to fail.

How about setting up a simple system that can't dose enough at any one time to spike your pH excessively?

You can dose kalk water at up to .25% system volume without pH problems.

Per Randy's article:

http://www.reefkeeping.com/issues/2005-01/rhf/index.php

"Delivering a small amount of limewater all at once. Adding 1.25% of the aquarium’s volume (1.25 gallons of limewater per 100 gallons of aquarium water) as saturated limewater all at once raises the pH by 0.6 to 0.7 pH units. Such an increase is clearly too large. Adding a smaller portion all at once can, however, be acceptable. Adding, for example, 0.25% of the aquarium volume (0.25 gallons or 1 L of limewater per 100 gallons of aquarium water) will raise the pH by only 0.1 to 0.2 pH units. Unless the pH is high (>8.4) before the addition, that amount is likely acceptable. The other concern with all-at-once dosing is that the local pH in the area of the addition will rise considerably higher than the values above. So dosing must be done far from living organisms, and in high flow areas that will facilitate fast mixture. In some aquaria, such restrictions make all-at-once dosing of limewater prohibitively risky to living organisms."

Temporary high local pH if you're dosing into a sump shouldn't be a problem. And it even helps to precipitate your phosphates.
 
So for my 100 + sump area, a liter is ok to dose, wow I might just do that, and then just pseudo drip at night.

I still want to get an ACJr or something though just to record the temperature and pH changes, maybe figure oout if things are swinging too much.

Although I did see a big mother of an "emerald" crab last night and and some missing flesh around the bottom of the "Jim Coral" I'm unsure if they are related though.
 
[quote author=sfsuphysics link=topic=2586.msg26878#msg26878 date=1195225255]
So for my 100 + sump area, a liter is ok to dose, wow I might just do that, and then just pseudo drip at night.[/quote]

That's basically what I'm doing. I'm splitting up a 1.25 gallon addition into 7 doses during the lights off period.

I'm using a digital timer that increments down to 1 minute, and can do 7 complete on/off events.

I tried doing 1 liter at a time, but I was getting too much carbonate precipitation in the sump.
 
Just about.

Something like .8 - 1 liter over 4-5 minutes through an Aqualifter.

I ended up cutting back to .6 liters over 3 minutes 7 times.

Supposedly not ideal to run kalk water through an Aqualifter, but I tried to find horror stories about that and didn't come up with any. I did find reports of people doing periodic cleaning on the pumps and not having problems. Even found reports of people running kalk through their pumps for 1 and 2 years without cleaning and without failures.

Anyway, I set up my kalk doser so that it in case of pump or power failure, nothing can siphon into the sump or onto the floor.

I could be in slight trouble if the digital timer fails on somehow, but I think that's supposed to be unlikely. I'm using a 5 gallon bucket for a kalk reservoir so the total amount of kalk dumped would be limited too. Plus it would snowstorm and precipitate to limit alk levels anyway.
 
a doser and an acjr will work wonders for you guys.

a litermeter3 is an amazing piece of reefing equipment. that and a controller. the lm3 will dose 150 times over a 24 hour period. i used to dose kalk from a geo reactor with the lm3, but then my demands grew, so i bought a second pump, ditched the geo, and dose two part the same way. no need for a kalk reactor as i do not have any ph issues.

best part its all real time...all digital. you can see the changes that happen, eg:

say alk is low. add little baking soda. acjr will show ph drop in real time. for every .04 unit decrease in ph, alk increases by .5 meq. so set the alk where you want it with soda, then bump the lm3 alk pump up a notch, say .01, .02, .03, .1, .2 ml, any increment, do the same for the calcium pump, and voila.
 
That whole recording thing is what really turned me onto the ACjr, to try to get some sort of quantitative analysis to what might be happening.
 
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