alk low, pH high - again

[bluespotjawfish]

I don't even know how to ask the question. I guess I want to know if I should dose the alk with the pH this high? But my questions also is about how the new turf scrubber is affecting pH. I've always had problems with CO2, so I'm sure it is helping fix that, but I didn't expect 8.5 with alk levels at 148. Anyway, here are tonight's results, what should I do:

12/11/08
148 ppm alk
410 ppm calc
1290 ppm mag
1.025 salinity
78.8 temp
8.54-8.55 pH (pm) (Tested with two different pH probes, including my brand new and recently calibrated RF.)

Other information that may have some meaning: I added a turf scrubber about 10 days ago. I have had several days since then where the pH read 8.5 or more, but then overnight drops to 8.0-8.1. My last WC was Sunday (a small one ~8 gallons on 125g tank). I dose kalk through my ATO. Evaporation rate is 3-4 gallons per day. The lower alk and calc levels are from the increasing demands of my SPS that the kalk reactor can no longer keep up with. (I just bought a Geo612 to hopefully correct that problem, but haven't installed it.) Here are some other recent test results:

12/6/08
132
400
8.06 (am)
1290
1.025
77.6
(I dosed 2 Part alk and calc)

12/3/08
(low, but pH high end)
144
385
8.4
1350
(I dosed 2 Part alk and calc)

11/30/08
(This is more typical and is about what my WC water mixes up at.)
184
425
1320
8.15
77.4

 

[bluespotjawfish]

:time: I guess I'm on my own.

Yesterday..
8.20 pH (am)
Dosed alk/calc (35 ml each)

8.47 pH (pm)

Post 8 gallon WC 8.26 pH

I will run all tests again today.

 

[cheeks69]

Are you using kalkwasser ? What are you dosing for alkalinity ? You say alk is at 148 or 14.8 ppm ? Are you using a ph buffer ? Which test kits are you using ?

 

[bluespotjawfish]

LaMotte for Alk; Salifert for everything else.
Kalkwasser is dosed using a reactor through my ATO.
Supplement with Baked Baking Soda (Randy's 2 Part).
No pH buffer.
148 ppm (note LaMotte reports this in ppm)

 

[cheeks69]

IMHO would stop the addition of kalk until you get your ph lower. I'm sure Boomer will chime in soon as I don't know the conversion between ppm and dKH.

 

[bluespotjawfish]

So stop the kalk and do 2 part only?

 

[cheeks69]

So stop the kalk and do 2 part only?

Yes at least until you have your ph under control.

 

[bluespotjawfish]

I usually have lower pH on this tank because of CO2 problems, so this is new to me. I do have a lot more surface oxygenation with the scrubber and how the drain now enters the sump, but it seems high even with that considered.

BTW, I have a GEO612 calcium reactor sitting here ready to hook up too. I haven't hooked it up yet because I wanted to get this problem figured out before I added any thing else new to the tank.

I think I will go run my tests now.

 

[bluespotjawfish]

I just ran my tests. I've decided that it is the pH probe.

148 ppm alk
405 ppm calc
1310 ppm mag
78.4 degrees
1.025 salinity
8.38 (ACJr Probe) / 8.27 (new RF Probe) / 8.2 (API test kit)

 

[BobBursek]

I donot know how to relate ppm to dhk on your Alk, but everything else lost right one for tank params.

 

[BobBursek]

that was suppose to be " looks right on for tank params"

 

[bluespotjawfish]

I put the kalk back on line last night. This morning I dosed 35 ml of Part 1 and Part 2. This evening's pH readings:

New RF 8.35
Old ACJr 8.26 (yesterday this read higher than the new RF)

I also put the calcium reactor together and tested it in the sink. Still need to get some CO2, but other than that I am all ready to start using it. I also have a new probe for the ACJr that I will install and calibrate when I can. One probe will be in the reactor chamber, the other in the tank.

:snowski:

 

[bluespotjawfish]

8.45 pH yesterday's high w/new RF probe
8.50 pH today's high w/new RF probe

grrr

 

[bluespotjawfish]

8.40 yesterday's high
8.44 today's high

124 ppm alk
420 ppm calc
1350 mag
78.7 temp
1.025 salinity

Dropping to about 8.08 at night

 

[cheeks69]

That's a big drop, how are your corals doing ? I'm surprised that with the dripping of kalk your ph doesn't stay a little higher during the night, where's Boomer...lol

 

[prow]

your alk is a little to low but not bad. a 124ppm is about 2.4 meq or 6.9 dkh.. i would stop with all dosing, maybe add some alk, like seachems reef builder (not buffer)then maintain your alk at about 3.0 meq or 150 ppm or 8.4 dkh and keep your Ca+ up with something like seachems adv. Ca+ until your ph, alk and Ca+ are inline. then start up the kalk again and dont dose the two part..if you go with kalk then i would just add reef builder or CaCl-(adv. Ca+) to keep things balanced. if you go with a two part additive then i would not use a reactor also, just use CaCl- and alk sup to balance things if needed. i only say this because two part solutions are not equal in their two parts, some have more of this buffer or acid, or more of that type of Ca+ and more than likely if used with a kalk drip things might not balance as you would like(think)....

 

[bluespotjawfish]

Thanks guys! At least now I don't feel like I am alone. I'm more worried about the swing than the actual pH. It drops pretty fast when the lights go out even though I have about 200 watts running in the fuge overnight.

The corals seem to be doing ok. I did lose a few very small pieces of SPS a few days ago, the rest look good. I also lost an anthia (don't know if it is related or not). The aiptasia is thriving!

I will leave the kalk on overnight to keep the pH up as much as I can, but turn it off in the morning before work. I will dose Randy's Part 1 by itself tonight before I go to bed and again in the morning.

The tank typically does use more alk than calc. I periodically have to dose the Part 1 by itself. I haven't been doing that because of the high pH.

I also have (but typically don't use) the following if any of these would be better:

Superbuffer-dkH (Kent)
Marine Aquarium pH Buffer (Kent)
Tech CB (A two part by Kent)

 

[prow]

if you always get big swings you could just do that, drip kalk at night and turn off your ATO durring the day. thats a good idea, that might work for ya, but i would look into fixing the CO2 issue in long terms. doing the above is just a bandaid, IMO. is it possible to run some sort of air duct to your tank? have you tested for CO2, in the tank and your home?

 

[bluespotjawfish]

Yea, been through all of that Co2 troubleshooting. I had a tube from the skimmer hanging outside my window for months, a million fans and pumps. I typically get a swing of about 0.2 and some of that is because the tank evaporates more during the day than overnight.

Do you think that if I use a perabolic pump for the kalk set to run each night and the new calcium reactor running 24/7 would work? The reactor is sitting here ready to plug in, but I want to stabilize stuff before I mess it up more.

 

[bluespotjawfish]

Yesterday I dosed 35 ml of Randy's Part 1 and later 4t of Kent's Superbuffer dkH.

142 ppm alk
8.2 pH (overnight)

I'm taking the kalk offline for the day.