Low PH

[SteedaSteve]

Hello all Kyla and I have a 55 gal reef tank and I have a PH tester that was part of a pool chlorine test kit (5 drops of the red stuff). I can not get my PH any higher than 7.8. I have been putting in 10 ml of KENT Pro Buffer dKH every day for over 2 weeks now and I still cant get my readings to go higher than 7.8. Any Suggestions?
Steve

[scuba_steveo]

top off with kalk water
That should do it.

[JimD]

And get yourself a good test kit designed for marine aquariums.

[GaryP]

And get yourself a good test kit designed for marine aquariums.

Yea, the phenophthalein in the marine kits is a lot better than the phenophthalein in the pool kits. It must be, it costs a lot more. :)

You probably need to check you alkalinity. Alkalinity is related to pH. I rarely test for pH. I know if the alkalinity is where it needs to be there is a good chance that pH will be OK too.

[matt]

There are all kinds of reasons you could be having a ph problem, if your ph is really 7.8, which you don't know without a calibrated probe, or at the very least an accurate test kit. The probe is much better. You should start by finding a reliable method of testing your ph, and maybe do a search to find previous posts that talk about ph. You can also search Randy Holmes-Farley on reefcentral to find articles he's written about ph. Then, if you determine your ph is really 7.8, that's not necessarily a problem, but might be an indication that something is off. But, since it's related to almost every other tank parameter, you'd have to provide lots more info before anyone could tell you what's going on. When you get a little more familiar with reef aquarium chemistry basics, you'll appreciate the interdependence between calcium, carbonate hardness, dissolved oxygen, (which you don't have to test for, but can insure you have enough of by using a good skimmer and/or providing lots of air/water exchange in a room that's not loaded with CO2)dissolved organics, temp, salinity, lights which drive photosynthesis, bio-load, etc....

Smile!

[GaryP]

Steve,

10 ml. of buffer is not a lot for a tank that size. That's one reason to get an alkalinity kit. The other thing to keep i mind is that pH varies at different times of day. Its usually lower in the AM when the lights first come on and increases during the day before starting to fall again after the lights go off. This has to do with the oxygen and carbon dioxide produced by algaes and other critters during the daily photocycle.

[gjuarez]

Yup, just like Gary said it. Like Gary, I never test for Ph either. I know it is where it should be since my alk is at 9-12 dkh. Get yourself a salifert test kit and you should do fine with that. Using Kalk as topoff, like mentioned earlier, is also a good idea. Drip it slowly though because you put it in all at once it can raise your ph a lot in a matter of minutes. Drip it prefferably at night before you go to sleep. Some people use baking soda but I do not have much info on that. Ask Gary about the Arm and Hammer.

[GaryP]

Some people use baking soda but I do not have much info on that. Ask Gary about the Arm and Hammer.

Actually, baking soda will raise alkalinity but will not raise pH. Baking soda has a low pH. A mixture of baking soda and washing soda will raise both pH and alkalinity.

[gjuarez]

Oh ok. So will washing soda itself raise the ph?

[GaryP]

Yes, you can use either washing soda or Kalk to raise pH. Washing soda is a little gentler than Kalk but has better solubility so you can add more. However, keep in mind with either that you never want to make a rapid change in pH. Washing soda can be dripped just like Kalk. With washing soda. you will raise pH and alkalinity. With Kalk, you can raise alkalinity too, but only to the extent that there is CO2 for it to react with. Washing soda is highly soluble in water whereas Kalk is only soluble to around 3% in water I think. A solution of Kalk has a pH of about 12-13, washing soda is about 9.5 as I recall.

Raising alkalinity rapidly can have some bad effects too, especially for crustaceans. I would suggest that you really know what you are doing before using Kalk. Its some nasty stuff and has the potential for really bad things to happen to your tank if you don't know what you are doing. It burns skin too, so if you get any on you, wash it off quickly. Ideally, gloves should be used when handling Kalk. I would never recommend dosing Kalk to a SW beginner unless you have someone to help mentor you on its application. The potential down side is really high (or is that low?)

Joshua, I think washing soda is perfect for use with a reactor, especially if you need some help with alkalinity. Buffer can be depleted faster than the calcium because there are other things besides coral that deplete it. If its just a matter of pH, then Kalk may be better than washing soda. I would suggest trying both and see what works better for you. Washing soda is definitely cheaper than LFS Kalk. Of course you can also use pickling lime instead of LFS Kalk if you are just dripping it. From what JimD has said, pickling lime doesn't work well in a reactor because of the residue it leaves in the reactor. In a drip jug like I use its not a big deal because I can wash it out occasionally.

[GaryP]

I just wanted to add something to my previous post about other things depleting buffer besides coral growth. Microbiological activity such as bacterial action in a wet/dry, LR, and LS produces organic acids such as acetic acid (vinegar). These acids are neutralized by the buffer (alkalinity) but are also depleted by them. In the case of acetic acid, calcium acetate is formed and actually becomes a minor part of the buffering system but does not show up in your test for alkalinity. That test only measures carbonate buffering (carbonate and bicarbonate).

If you have a system with a high bioload that means you are going to have more of these acids being formed. This can result in higher depletion of buffer by non-calcification (coral or coraline algae growth) mechanisms. By heavy bioload, I not only mean high levels of livestock stocking, but also systems that are being overfed and have a lot of biological action taking place to handle the excess waste resulting from uneaten food that becomes part of the detritus in the tank.

I wish I had added a Microbiology 101 topic to the list of topics for future meetings. It all ties in together eventually.

[GaryP]

One more thing. According to Martin Moe, the typical buffer contains a ratio of 6:1 baking to washing soda (bicarbonate to carbonate). If you are having problems with a low pH you can adjust that ratio to 5:1 or 4:1 to help adjust the pH in a less drastic way, without going to dosing of straight washing soda.

I should say that I think that folks get more freaked out over a low pH more than they really need to. A pH of 7.8 is not really a problem. If it was much lower than that I think it needs some sort of corrective action. A pH of 7.8-8.4 is an acceptable range IMO. I have run mine as high as 8.5-8.6 to help eliminate a dinoflaggelate problem. I wouldn't suggest anything lower than 7.8 though unless it was a taken first thing in the AM after lights came on.

OK, I probably have everyone totally confused by now and I'll shut up.

[GaryP]

I'd also have to buy batteries for my ph tester if I were to want to dump pure washing soda, they ran out about a year ago. :lol

I admit I do own a pH test kit, I'd just have to look for it. If it wasn't for raising the pH because of the dinos I would probably rarely use it.

[JimD]

Because I use a kalk reactor, I monitor Ph continualy, it lets me know when to recharge the reactor. I dont mess wth the home brews, its strictly kalk and B-Ionic for me.

[GaryP]

Jim,

Do you just use the buffer component of B-Ionic or do you have to add calcium too?

[JimD]

Gary, I use equal ammounts of both. Like 15ml or so once a day. To be honest, I havent checked Ca in months, I rely on coral growth to let me know if theres a problem, so far, so good. I like the reactor because it stalilizes night time Ph and maintains Ca and Alk. I have ridiculous coral growth.

[NaCl_H2O]

Well, I still battle this balance continuously! I belive my load has finally increased with the clam tank so that my Ca dropped to around 400. I have a Ca reactor, drip (Ha, BIG drips) Kalk, and add Buffer or B-Ionic when appropriate.

dKH is 9-10, can't get it much higher for extended periods
PH is 8.0-8.1, I have cranked up the Ca Reactor which may be depressing PH?
Ca is 400-425

I seem to have very good coral growth, not sure if it is "Rediculous" ;)

[GaryP]

Steve,

I wouldn't change a thing. You are at or above SW levels for all the parameters you mentioned.

[NaCl_H2O]

I wouldn't change a thing. You are at or above SW levels for all the parameters you mentioned.

Forgot to mention, all parameters reported are 10% higher than actual due to wishful thinking ;)

Yea, I think I'm OK - but what would I do everyday after work if I couldn't test parameters and "tinker" :D Keeps me out of the LFSs ;)

[JimD]

The only thing I might tweek would be the Ph, maybe just a tad higher, around 8.3 or so. What time of day are those readings from? Whats it at at night? Possibly encourage more evaporation to cmpensate for the cranked up Ca reactor.

[NaCl_H2O]

What time of day are those readings from? Whats it at at night?

Good point - these readings are typically when I get home from work at around 7:00pm.

I think I am a little bass akwards on my Kalk timing. I let the Kalk mix overnight and settle for 3+ hours before the top-off system comes on in the morning and then remains on all day. First thing in the morning the tank gets a healthy dose of Kalk water, and PH gets a healthy boost, but not extreem (maybe 0.1 at most), and the top off is throttled back so the RO/DI has to refill it before the pump can kick on again. Probably takes 2-3 hours for all the evening evaporation to be topped off.

Evaporation is good, and increasing now due to weather (AC runnning more). I have a Dehumidifier that I dump about 3/4 gallon out of twice a day :o

[JimD]

hhmmmm,,,, might wanna re-think that approach. Try mixng the kalk about three hours before lights out, that way when the lights are out and Ph bigins to drop, youll have a fresh batch of effluent to drip throuout the night maintaining youre Ph at the higher level. During the day, you should see a noticable increase in Ph.

[NaCl_H2O]

I have almost changed the timing a few times, but I am paranoid. My top-off got stuck on once and severely overdosed Kalk, so I like being able to check it out first thing in the morning before I leave for work.

Definatey worth reconsidering - Thanks!

[GaryP]

Steve,

With that huge fuge on your system I wouldn't think you would get much of a nighttime dip in pH. Are you running your fuge lights 24/7 or on reverse cycle?