Apex salinity module... question.

kris2001 · Oct 24, 2019

Hello,
I've been using RKL in my last 75g. Used for lights, doser, Mh lights e.t.c.

Might get an apex classic... used. .. for my new 150g build.

I think i like the fact that it can be monitored, controlled via app in phone.

Also i have a specific question on salinity module:

Why is it not denoting in s.g. ie 1.025 instead does another format i forgot... it runs in the 30s.!

How efficient is the salinity probe? How long does it usually last till needs a replacement?

If it does need replacement how to find that out early on?
How often do i calibrate it?

If probe lasts long and is dependable i might go with the apex classic comes with temp, ph probes, display and 1 apex power strip unit for like $220 ... from a local reefer. I'll then buy salinity module and ORP.

Also to control calcium reactor is apex better than RKL?

THANKS!

vetteguy53081 · Oct 24, 2019

I find the probe less than accurate as well as many others also. If kept clean and calibrated regularly..... it gives you a good idea . The ppt is metric reading based on its’ design. Conversion is super easy
I verify y salinity reading on apex against refractometer

Sleepydoc · Oct 24, 2019

The salinity probe is probably the worst part of the Apex controller. It's not terribly accurate and prone to electrical interference. Much of this is due to the intrinsic difficulties that come with a conductivity probe for continuous use, so it's not all Neptune's fault. Either way, as luck would have it, it's also the least important probe. I quit looking at mine long ago.

kris2001 · Oct 24, 2019

How about the temp, ph probes in apex ?
How often to replace, accuracy?

Just trying to justify switching from RKL to apex classic on budget lol.

I have 2 cameras monitoring tank and temp, sump ATO levels. In emergency while vacationing it needs human interference that my reefer friend can fix.

Just wondering is it worth the switch.

Can RKL work with calcium reactor same way apex classic does? Is that a different ph probe for reactor control( solenoid)?
Used to dose before now trying reactor.
Thx

foxt · Oct 24, 2019

kris2001 said:
Why is it not denoting in s.g. ie 1.025 instead does another format i forgot... it runs in the 30s.!

"salinity" is measured as the ratio of the weight of the salt to the weight of the water. This is reported as ppt, or parts per trillion.

"specific gravity" is measured as the relative weight of salt water to pure water. There are no units, it's just a number.

Apex is reporting the salinity (in the 30's), and you're expecting specific gravity (1.02x). The two different measurements correlate for a given temperature, if you look on a refactometer it usually has the scales side by side.

kris2001 said:
How efficient is the salinity probe? How long does it usually last till needs a replacement?

If it does need replacement how to find that out early on?
How often do i calibrate it?

As others have said, many people skip the salinity probe because it is difficult to keep calibrated, seems to have a mind of its own at times. Some people do find it useful to flag rapid changes, which might mean your ATO has gone haywire. There are other ways to accomplish that though. So it's one of those "eh, maybe" type things.

foxt · Oct 24, 2019

kris2001 said:
How about the temp, ph probes in apex ?
How often to replace, accuracy?

Just trying to justify switching from RKL to apex classic on budget lol.

I have several different systems running on a variety of Apex controllers, classic, jr, gold. I don't think I've had a temp probe fail on me yet. The pH probes do fail, I think I tend to replace them about once a year or so. Regardless of what kind of controller you use, you do need to check the pH probe calibration on a regular basis. I use non-Apex brand pH probes, and they are plenty accurate for my purposes.

kris2001 said:
Can RKL work with calcium reactor same way apex classic does? Is that a different ph probe for reactor control( solenoid)?
Used to dose before now trying reactor.
Thx

I started with a RKL, but at some point decided I needed a better interface and more options so I moved to GHL for a while. I like the GHL stuff, but I am like you, I like to save money and buy used stuff, so I was able to pick up a used Apex Jr with lots of extras for little money. Both GHL and Apex have been working fine for me, but I found the interface on Apex to be more intuitive so whenever I start a new tank, I look for used Apex stuff.

You can run a calcium reactor with a RKL, controlling the pumps and the CO2 solenoid. The trick with a reactor though is to tune it so that the controller does not need to keep turning the CO2 solenoid on and off - you use the controller as a failsafe so that if the pH in the reactor is dropping for some reason, you can shut it down and have it tell you there is a problem to be investigated. There are lots of threads on how to run a reactor with a controller ...

mcdrichj · Oct 24, 2019

SG or specific gravity which is the weight of a specific volume of water compared to the weight of the same volume of seawater is 1.025-1.026 SG. PPT is parts per thousand which is a concentration for sea water is 34-35 PPT. PPT is not metric its a ratio just as SG is also a ratio.

SPR1968 · Oct 24, 2019

All my probes have been in for around 3 years and seem all ok other than the salinity probe normally starts giving false ‘wild’ readings after around 3 months when its telling you it needs cleaning.

I also have to calibrate it with my tank water when I’m happy it’s at 35ppm with my trusty refractometer as it never works with the solution

kris2001 · Oct 29, 2019

Thx.
With apex classic, I'm getting a used pkg deal incl a netgear wireless adapter.
Will classic work wireless connected to home internet via this adapter, anyone has had issues with the connection using an adapter like this?

Also with respect to MH lighting, it needs more accessories in RKL (more wiring) compared to apex classic, am I right? I think i can plug in MH ballasts 250w plugs directly into the eb8 , correct?

kris2001 · Oct 29, 2019

kris2001 said:
Thx.
With apex classic, I'm getting a used pkg deal incl a netgear wireless adapter.
Will classic work wireless connected to home internet via this adapter, anyone has had issues with the connection using an adapter like this?

Also with respect to MH lighting, it needs more accessories in RKL (more wiring) compared to apex classic, am I right? I think i can plug in MH ballasts 250w plugs directly into the eb8 , correct?

Sorry forgot to mention the model #
NETGEAR (PLW1000)

Hallowhead · Oct 29, 2019

foxt said:
I have several different systems running on a variety of Apex controllers, classic, jr, gold. I don't think I've had a temp probe fail on me yet. The pH probes do fail, I think I tend to replace them about once a year or so. Regardless of what kind of controller you use, you do need to check the pH probe calibration on a regular basis. I use non-Apex brand pH probes, and they are plenty accurate for my purposes.

I started with a RKL, but at some point decided I needed a better interface and more options so I moved to GHL for a while. I like the GHL stuff, but I am like you, I like to save money and buy used stuff, so I was able to pick up a used Apex Jr with lots of extras for little money. Both GHL and Apex have been working fine for me, but I found the interface on Apex to be more intuitive so whenever I start a new tank, I look for used Apex stuff.

You can run a calcium reactor with a RKL, controlling the pumps and the CO2 solenoid. The trick with a reactor though is to tune it so that the controller does not need to keep turning the CO2 solenoid on and off - you use the controller as a failsafe so that if the pH in the reactor is dropping for some reason, you can shut it down and have it tell you there is a problem to be investigated. There are lots of threads on how to run a reactor with a controller ...

How often do you truly calibrate ph probe ?

foxt · Oct 29, 2019

It depends on what readings I am seeing, but I would guess maybe every 3 months or so? There are times when the pH reading from the tank or the CaRx will look off, and the first thing I do is calibrate the probe.

Bryknicks · Nov 21, 2019

SPR1968 said:
All my probes have been in for around 3 years and seem all ok other than the salinity probe normally starts giving false ‘wild’ readings after around 3 months when its telling you it needs cleaning.

I also have to calibrate it with my tank water when I’m happy it’s at 35ppm with my trusty refractometer as it never works with the solution

I've never been able to get my probe to properly calibrate using solution. How do you calibrate with the tank water. Is it as simple as calibrating the probe dry, then just in the tank water as if it was calibration solution (obviously confirmed with a refractometer)?

SPR1968 · Nov 21, 2019

Bryknicks said:
I've never been able to get my probe to properly calibrate using solution. How do you calibrate with the tank water. Is it as simple as calibrating the probe dry, then just in the tank water as if it was calibration solution (obviously confirmed with a refractometer)?

Exactly yes. When it says put the probe in the solution, just put it back in your tank and finish the calibration as if it were in solution, but only when your happy that the salinity in your tank is were you want it.

I find the probe needs cleaning every 3-4 months (it goes crazy!) so I just wait until I’m happy the salinity is correct from my refractometer and then calibrate the probe.