pH parameter

[KoiTang]

Do any of you guys have an issue with high pH? My problem is that my alk goes down quick but I can't add in two part Alk because it will drive the pH super high without adding in vinegar to lower the pH. Is there any other way to do this? It seems my co2 is low in my tank. Is there such a thing as log c02? Because of lowering the pH and then increasing it with Alk seems to have triggered RTN on some of my SPS. Let me know your thoughts. Here's my parameters:

pH 8.4
temp: 79F
Calcium: 460
Mag: 1375
phophate: .003
Nitrate: 5ppm

 

[jsker]

What is your alk, and how old is your system

 

[Sabellafella]

Do any of you guys have an issue with high pH? My problem is that my alk goes down quick but I can't add in two part Alk because it will drive the pH super high without adding in vinegar to lower the pH. Is there any other way to do this? It seems my co2 is low in my tank. Is there such a thing as log c02? Because of lowering the pH and then increasing it with Alk seems to have triggered RTN on some of my SPS. Let me know your thoughts. Here's my parameters:

pH 8.4
temp: 79F
Calcium: 460
Mag: 1375
phophate: .003
Nitrate: 5ppm

You have to dose alk in small doses to accomidate for the ph swing. Do you dose all at once? Or use a dosing pump?

 

[KoiTang]

Alk is 8.4 but then it drops to the low 7s in a day or two. I dose manually right now and break it up in small doses every 1 hour after lights go off and then again in the early morning til I go to work. Dosing about 20-30mL so about 5-10 mL each dose. I dose everyday. System is over a year old. I have alot of SPS in a 70 gallon tank so it consumes a lot of alk/calcium but pH is just high.

 

[goatcorals]

I mix soda ash (raises ph) with sodium bicarbonate (lowers ph slightly) to manually dose. This mitigates the upward ph swing it seems.

 

[Sabellafella]

Alk is 8.4 but then it drops to the low 7s in a day or two. I dose manually right now and break it up in small doses every 1 hour after lights go off and then again in the early morning til I go to work. Dosing about 20-30mL so about 5-10 mL each dose. I dose everyday. System is over a year old. I have alot of SPS in a 70 gallon tank so it consumes a lot of alk/calcium but pH is just high.

I wouldnt worry, assuming you monitor ph with a probe,your swing Is how big daily?

 

[Anthony Wood]

pH is a measure of OH- (minus negative charge) and H+ (plus positive charge). CO2 will drop pH and O2 will raise it. Good surface agitation puts O2 into the water that'll raise pH granted your dKh is above 7.0. The organisms in your tank will create O2 which is why pH should be highest lights on. The organisms in the tank the stop producing O2 at night why the pH drop should be at night. Yes you'll get a momentary pH spike when you add two part alk but shouldn't too Much to cause concern if it does try dosing farther away from the probe or do smaller amounts spread out through the day. A small spike will drop back down to where it should be after the ions balance themselves out.

When is the last time that probe has been cleaned with probe cleaning solution? When was it last calibrated after using probe cleaning solution? How old is the probe? The could be your issue. Probes are only good for about a year then shouldn't be trusted.

If you have good surface agitation and air flow on the tank I wouldn't worry about your pH.

 

[KoiTang]

Surface agitation is good. pH is new. 1-2 month old. I only use it when I need it so it does not run continuously. To me it seems like the pH does not drop back down. If I keep the alk at 8.5dkh by adding in alk, it spikes to 8.5pH. Then the next day, it will spike to 8.6ph when adding pH. The day after that it would spike to 8.7dkh. pH seems to be going up slightly if I want to maintain a 8.5dkh. Now I could be wrong and maybe it may level it self out eventually but I dont want to take the risk.

 

[Anthony Wood]

What are you storing the probe in when it's not in use? Or does it stay in the water? Every time it leaves the water and into storage the next time you put it back into the water it needs to be calibrated. There's also a storage solution for the probe usually a KCl solution to be sure that the probe tip doesn't dry out. The glass ball on the end is actually porous on a ion level which is how it works. If allowed to dry overnight even once the probe is no good. If you have any doubts I have a B.S. in chemistry I was in a lab for 4 years working with these type of things lol

 

[KoiTang]

The ph probe is stored in its solution. I compared it with my old ph probe and they are both reading the same. Both probes are still accurate as I've used it at buddies tank a few weeks back to compare it to his new neptune setup. They were pretty much the same.