Reef Crystals & Instant Ocean -- Extremely Low PH

[z28pwr]

Is it just me or what. 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...



Am I the only one with this problem ?

[chark]

When I made new water I checked my Reef Crystals last week and it was 7.8.

[Ping]

I do not run a Calcium Reactor so I do not check my pH. I just make sure the Ca and Alk levels are within range.

Newly mixed synthetic seawater is not saturated or stable. Conduct the water change and make adjustments to the main system.

[Ping]

As well as Alk levels and to further explain:

I have an overflow, sump and skimmer for gas exchange.

[OrionN]

Check it after you mixed for at least 1 day

[Bill S]

You really have to make sure it's completely oxygenated. CO2 levels will dramatically affect pH, and with carbonates in the mix, you need to make sure to drive any CO2 off.

[OrionN]

I usually agitated my water with a PH with some air intake to keep it oxygenated also. I almost never use newly mixed salt water for at least 1 day. Newly mixed water is not stable and toxic to fish and other animals. You can get away with using newly mix water if you only change perhaps up to 25 % of the water. IF you change 100% of the water, fresh mix salt water will kill most of you fish and invertebrates.
How long do you have to wait until you can safely use it? I don't know but I have change 100% of my water using 1 day mixed water without problem.
BTW, pH probe are notorious for not given accurate pH reading. You have to calibrate it essentially every time you use it. Too troublesome for me to use.

[Bill S]

Minh,

I'm sorry, but I do this all the time. My nano gets a change of about 50-60% regularly - and there are a pair of clowns, a blenny and a RTBA, along with some other critters. Usually gets mixed for a hour or 2.

Frankly, I use large quantities (over 25%) of newly mixed salt all the time. I make sure it's clear, and that it's been decent oxygenated.

[NeptunesGhost]

I am with Orion on this. I always mix my salt (Red Sea Pro) a minimum of 24hrs prior. It is mixed in a 30G barrel with a K4 mix pump and an air-stone for oxygenation. This gives the water a chance to stabilize. Generally, my PH is a bit high, not low. I guess I could be oxygenating too much.

[rz1a]

Same here, I mix minimum one day before, or a few days in advance. I have a 32g brute trash can with a maxi-jet and sure flow mod. I never really check pH either as long as the alk and cal are within the ranges i need

[NeptunesGhost]

Minh,

I'm sorry, but I do this all the time. My nano gets a change of about 50-60% regularly - and there are a pair of clowns, a blenny and a RTBA, along with some other critters. Usually gets mixed for a hour or 2.

Frankly, I use large quantities (over 25%) of newly mixed salt all the time. I make sure it's clear, and that it's been decent oxygenated.

Out of curiosity, how do you check oxygenation? As I said, I may be over-oxygenating.

[OrionN]

I know that if I change 100% of the water, I used aged (1 day) water and have no problem. The one time that I changed 75% of the water using fresh mix water, my coral all stressed out and a few mortality resulted, including fish. Everything was disolved and the water was clear and well oxygenated. I did not try to use freshly mixed water after this event.
There are plenty of reading material over at the Chemistry forumn at Reef Central on this topic.

[OrionN]

Open container with something to aerated the water would be sufficient to assure well oxygenated. I don't think you need to worry about over Oxygenation (unless you use 100% oxygen). I don't think you need to check the oxygen level

[NeptunesGhost]

I ask because low oxygen in water causes low PH correct? The PH of my freshly mixed and aged water is 8.8 using PH 7.0 RODI (0tds) water. I have Red Sea working on that too.

Sorry, didn't mean to hijack, just trying to clear things up.

[OrionN]

pH is more of a function of CO2 in water rather than O2 (and other dissolved acid and base) CO2 dissolved in water to form H2CO3 = H+ and HCO3-. Agitated water will make sure that all the CO2 escape to the atmosphere.
Sorry for all the misspell words. I was in a huge hurry this afternoon.

[wesheltonj]

When I first started, I waited 48 hours, then that went to 24, now its 12. I mix it the night before, place in 1 or 2 Maxi-jet 900's depending how much water I am mixing up (I use to use 1200's, but the 900's have a much smaller power draw and I am just mixing water). I have use fresh mixed water in as little as 15 minutes, but only like 10% of tank volume.

[DrMark]

I try to mix water night before, but often is just several hours before change, no air stone, just a strong pump. I am only changing about 15% volume though.
mark

[Agent Jones]

i try to mix a day in advance and that seem to help alot