Alk normal, big pH swings

[Brooks Talley]

Hi everyone. I had a beautiful reef tank for years that I operated on
the sheer-dumb-luck principle. Occasional water changes were the
extent of the maintenance, and it thrived. No skimmer, no water
tests, etc. Somehow it worked out.

After moving, though, the dumb luck stopped working, so I'm having to
actually get educated on how this works. I've equipped my 100g tank
with a skimmer and an aquacontroller II with ph, orp, and temp probes,
and a medusa temp controller with a 300w heater and 1/3hp chiller
(it's warmer down here in san diego).

Right now, the tank stats are:
- Alk 3.0 (fastest kit)
- Temp 80f
- SG 1.023 (refrectometer)
- Nitrate 0 (salifert kit)

.... and then what I think is a problem, the pH swings from a high of
about 8.5 at night to a low of 8.0 in the morning just before lights
on.

By my read, that's a big swing considering the 3.0 alk. Am I correct
in thinking that that's a problem, and if so, where should I be
looking for the cause?

The tank is very, very lightly stocked. Maybe 8 turbo snails, 20
small red legged hermit crabs (I had an algae outbreak), one bubble
tip anemone. The anemone seems to be just hanging in there, and the
various small creatures on the live rock seem listless. I'm afraid to
add anything else until I get this sorted.

Thanks
-b

[Boomer]

"By my read, that's a big swing considering the 3.0 alk. Am I correct
in thinking that that's a problem, and if so, where should I be
looking for the cause?"

In most systems, to include natural systems, a swing in pH is rarely do to any change in
Alk. pH will go up or down depending on the amount of CO2. CO2 has no effect on alk or
vise versa but has a large impact on pH. There are few things that cause this.

1. Heavy load of organics, much getting converted into CO2

2. Poor nutrient export, usually not good enough skimming, actually part of 1.

3. Heavy algae growth, as I suspect for your tank. The algae consume the CO2 during the
day, raising the pH but at night expel CO2 lowering the pH. There are a couple of ways of
correcting this. Dripping kalk at night has long as it does not end up raising the Alk and
Ca to much. A refugia on reverse lighting

4. Excess room air CO2.

5. To some extent poor circulation





--
Boomer

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If You See Me Running You Better Catch-Up
"Brooks Talley" > wrote in message
om...
: Hi everyone. I had a beautiful reef tank for years that I operated on
: the sheer-dumb-luck principle. Occasional water changes were the
: extent of the maintenance, and it thrived. No skimmer, no water
: tests, etc. Somehow it worked out.
:
: After moving, though, the dumb luck stopped working, so I'm having to
: actually get educated on how this works. I've equipped my 100g tank
: with a skimmer and an aquacontroller II with ph, orp, and temp probes,
: and a medusa temp controller with a 300w heater and 1/3hp chiller
: (it's warmer down here in san diego).
:
: Right now, the tank stats are:
: - Alk 3.0 (fastest kit)
: - Temp 80f
: - SG 1.023 (refrectometer)
: - Nitrate 0 (salifert kit)
:
: ... and then what I think is a problem, the pH swings from a high of
: about 8.5 at night to a low of 8.0 in the morning just before lights
: on.
:
: By my read, that's a big swing considering the 3.0 alk. Am I correct
: in thinking that that's a problem, and if so, where should I be
: looking for the cause?
:
: The tank is very, very lightly stocked. Maybe 8 turbo snails, 20
: small red legged hermit crabs (I had an algae outbreak), one bubble
: tip anemone. The anemone seems to be just hanging in there, and the
: various small creatures on the live rock seem listless. I'm afraid to
: add anything else until I get this sorted.
:
: Thanks
: -b

[Boomer]

I forgot

"SG 1.023 (refrectometer)"

Is way to low. Refracts are off .0015 from the factory, when compared to seawater so

1.023 - .0015 = 1.0215 = a NSW Salinity of 29 ppt and NSW is 35 ppt. You need the refract
to read about 1.028 = 35 ppt or 1.0265 NSW + .0015 = 1.028. Low salinities are stressful
on many inverts


--
Boomer

Want to talk chemistry ? The Reef Chemistry Forum
http://www.reefcentral.com/vbulletin/index.php

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Please Join Our Growing Membership
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If You See Me Running You Better Catch-Up
"Brooks Talley" > wrote in message
om...
: Hi everyone. I had a beautiful reef tank for years that I operated on
: the sheer-dumb-luck principle. Occasional water changes were the
: extent of the maintenance, and it thrived. No skimmer, no water
: tests, etc. Somehow it worked out.
:
: After moving, though, the dumb luck stopped working, so I'm having to
: actually get educated on how this works. I've equipped my 100g tank
: with a skimmer and an aquacontroller II with ph, orp, and temp probes,
: and a medusa temp controller with a 300w heater and 1/3hp chiller
: (it's warmer down here in san diego).
:
: Right now, the tank stats are:
: - Alk 3.0 (fastest kit)
: - Temp 80f
: - SG 1.023 (refrectometer)
: - Nitrate 0 (salifert kit)
:
: ... and then what I think is a problem, the pH swings from a high of
: about 8.5 at night to a low of 8.0 in the morning just before lights
: on.
:
: By my read, that's a big swing considering the 3.0 alk. Am I correct
: in thinking that that's a problem, and if so, where should I be
: looking for the cause?
:
: The tank is very, very lightly stocked. Maybe 8 turbo snails, 20
: small red legged hermit crabs (I had an algae outbreak), one bubble
: tip anemone. The anemone seems to be just hanging in there, and the
: various small creatures on the live rock seem listless. I'm afraid to
: add anything else until I get this sorted.
:
: Thanks
: -b

[Boomer]

"By my read, that's a big swing considering the 3.0 alk. Am I correct
in thinking that that's a problem, and if so, where should I be
looking for the cause?"

In most systems, to include natural systems, a swing in pH is rarely do to any change in
Alk. pH will go up or down depending on the amount of CO2. CO2 has no effect on alk or
vise versa but has a large impact on pH. There are few things that cause this.

1. Heavy load of organics, much getting converted into CO2

2. Poor nutrient export, usually not good enough skimming, actually part of 1.

3. Heavy algae growth, as I suspect for your tank. The algae consume the CO2 during the
day, raising the pH but at night expel CO2 lowering the pH. There are a couple of ways of
correcting this. Dripping kalk at night has long as it does not end up raising the Alk and
Ca to much. A refugia on reverse lighting

4. Excess room air CO2.

5. To some extent poor circulation


--
Boomer

Want to talk chemistry ? The Reef Chemistry Forum
http://www.reefcentral.com/vbulletin/index.php

Want to See More ?
Please Join Our Growing Membership
www.coralrealm.com

If You See Me Running You Better Catch-Up
"Brooks Talley" > wrote in message
om...
: Hi everyone. I had a beautiful reef tank for years that I operated on
: the sheer-dumb-luck principle. Occasional water changes were the
: extent of the maintenance, and it thrived. No skimmer, no water
: tests, etc. Somehow it worked out.
:
: After moving, though, the dumb luck stopped working, so I'm having to
: actually get educated on how this works. I've equipped my 100g tank
: with a skimmer and an aquacontroller II with ph, orp, and temp probes,
: and a medusa temp controller with a 300w heater and 1/3hp chiller
: (it's warmer down here in san diego).
:
: Right now, the tank stats are:
: - Alk 3.0 (fastest kit)
: - Temp 80f
: - SG 1.023 (refrectometer)
: - Nitrate 0 (salifert kit)
:
: ... and then what I think is a problem, the pH swings from a high of
: about 8.5 at night to a low of 8.0 in the morning just before lights
: on.
:
: By my read, that's a big swing considering the 3.0 alk. Am I correct
: in thinking that that's a problem, and if so, where should I be
: looking for the cause?
:
: The tank is very, very lightly stocked. Maybe 8 turbo snails, 20
: small red legged hermit crabs (I had an algae outbreak), one bubble
: tip anemone. The anemone seems to be just hanging in there, and the
: various small creatures on the live rock seem listless. I'm afraid to
: add anything else until I get this sorted.
:
: Thanks
: -b