Reef Crystals & Instant Ocean -- Very Low PH

z28pwr

New member
If I mix Reef Crystals with RO water to 1.025 sg I end up with a PH of 7.3 and if I mix IO to 1.025 I end up with a PH of 7.2. I checked this with both my Neptune PH Monitor and with a PH test kit. You would say big deal, just add some buffer but the buffer raises both PH and DKH which by the time I get the PH to 8.0 the DKH is at 16, thus I have to buffer it with Limewater to get it to 8.1 where I have the tank at. I thought maybe my refactometer is off (even though I just recalibrated it) but I followed their exact directions and mixed 1/2 cup of salt in 1 gallon of water and ended up with 1.025 SG with a PH of 7.3. I even recalibrated my neptune using a bag of 7 & 10 calibration solution, but the result was the same a ph of 7.3 even though the sg is at 1.025.



Am I the only one with this problem ?
 

Billybeau1

Premium Member
You should not concern yourself with the pH of freshly mixed salt water. It is not something to measure whether a salt mix is good or not.

I would measure your tanks pH and make the appropriate adjustments if needed. :)
 

Jeff

Premium Member
Billy is right. If you take some tank water that you just tested at a ph of 8.0 and let it sit out for awhile, the ph will drop.
 

mflamb

New member
I mix and aerate my Reef Crystal mix for at least 4 days before using it and the pH is always over 8.1
 

qfrisco

New member
Testing the pH of your water right after you mix it could be misleading as the gases in your newly mixed water haven't had a chance to equalize with the gases in the atmosphere. You need to let your newly mixed water continue to mix with a powerhead or aerator for a couple hours, giving a chance for that equilibrium to happen, then test your pH. I think you'll find that the pH will always be on target (at least that's my experience.)
 

THE ROOK

New member
I would also recommend getting some salinity calibration fluid. It's only $5.00 & would be much more accurate than your current method. Along the same lines, make sure your using PH 7.0 & 10.0 calibration fluids to set your PH probe.
 

curiouser

New member
I have similar problem as OP 8 years ago. I use Reef Crystals and trouble maintaining tank pH 7.8 or above. I use Milwaukee pH meter and recalibrated last week and again today with two different brands of pH test fluids. My dKH runs high as does OP's and a chart of 12 salt mixes shows RC with the highest dkh of the 12 mixes tested. http://www.thatpetplace.com/salt-mix-guide. Today the pH of RC saltwater mixed 6 days ago (with 48 hrs mixing with a powerhead) is 7.8 and dkh 9.6. I have tested RC pH before on different batches and pH has been 7.7, 7.8.
Has anyone had success in correcting low tank pH by switching salt mix brands? From which brands to which other brands?
Thanks
 

bertoni

Premium Member
pH at 7.8 is very common for a tank in the house with the windows shut. The indoor carbon dioxide level rises as people breathe. Lots of Tanks of the Month run at 7.8. Raising the level probably would require fresher air into the water. In some tanks, using a higher-pH alkalinity supplement will help a bit.
 

curiouser

New member
Thanks for responding. I've tried keeping a window open, doors shut and exhaust fan going for 16 hours in the room with the tank and no improvement. I couldn't go longer here in Atlanta as it's just too hot this time of year. I usually use kalk via Tunze Osmolator and Calcium Dispenser (5074). I've tried baked baking soda (sodium carbonate) which raises pH, but only transiently.
Sometimes the pH is 7.7, rarely 7.6 and that worries me re losing some tank animals.
Have you heard increasing reports of low tank pH as atmospheric CO2 is rising?
Am I overstating the risk of pH 7.7, 7.6?
Do you have any other suggestions?
Thanks
 

bertoni

Premium Member
I would try aerating a cup of water outside for three hours or so, and then measuring the pH. A powerhead would be fine. The pH should rise to at least 8.2-8.3. If not, some sort of measurement device isn't working, likely the pH unit, but alkalinity kits fail, too.
 

Cohibaman

New member
Typical reasons for low pH in newly mixed saltwater;

1) inaccurate pH measurement (crappy test kit, expired test kit, improperly maintained or dirty pH sensor, etc)
2) inadequate time mixing/aerating to allow proper gas exchange with ambient air.
3) if mixed/aerated for long enough (generally 24-48 hours) and it's still low, check the alkalinity. If alkalinity is ok, it could be (probably is) excess C02 in the air in your home, driving the pH down due to the formation of carbonic acid. Aerate outside and see if it increases. If it doesn't increase, it's either #1 above or #4 below.
4) bad salt mix (generally this isn't the problem, but it certainly could be the cause).
 

bertoni

Premium Member
Three hours with a powerhead should be fine for most salt products. I think it's more likely that the salt product would need time to drop to the proper pH than rise, but we do see a lot of variation in the various mixes.
 

tmz

ReefKeeping Mag staff
Premium Member
Aerating and mixing overnight is more than adequate IME.

pH is driven by CO2 in the water;at 7.7 and below coral skelton and other calcareous mass can begin to dissolve.

Steady alkalinity levels are very important for many corals, particulary stoney corals.So, raising pH with buffers is disruptive to constancy and more often than nt only has only a short term effect as CO2 from the surrounding air offsets the pH rising effect in a brief time.

Raising pH without disrupting alkalinity is possible even in inside areas where CO2 air levels are high :

via more fresh air to the fish room;
an outside airline to the simmer air intake;
a CO2 scrubber attached to the skimmer air intake;
dosing calcium hydroxide(limewater/ kalkwasser) in lieu of some or all of the carbonate/bicarbonate and calcium chloride being dosed
 

ssublime1

New member
Using soda lime in a media reactor hooked into my skimmer's air tube has worked wonders. I was going from 8.1 -7.7 before using it to now 8.3 - 8.1 as the norm. The downside to this is the soda lime only lasts about 2 weeks and is pretty expensive. However in my case it's worth it for stability sake.
 

tmz

ReefKeeping Mag staff
Premium Member
I also use a CO2 scrubber with soda lime with similar results . Mine lasts about 4 weeks but that's probably because the CO2 levels in the air in my house are relatively low.

Soda lime repackaged in hobby products is much more expensive than more generic sources. In the US, I get mine from on line medical or veterinary providers like med vet at a fraction of the cost; it is widely used for CO2 control during anethesia I diy'd the reactor from some juice bottles for about a dollar.
 
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