5 Day old Apex - Salinity/Conductivity Probe Already Going South

[burton14e7]

What I had been reading as the possible culprit for this is temp compensation but looking at my chart you can see there is no correlation between the two. I'm thinking the probe has already malfunctioned but thought I would check with the collective experience in the forum before I hit up Neptune. What are your guys thoughts? User error that I can correct or bad probe?

Things I already checked:

1. auto top off - sump level has been rock solid stable at the optical sensors on my ATK
2. my salinity is miraculously dropping for no reason - checked with my Milwaukee digital refractometer which has temp compensation and my salinity is rocking a solid 1.025
3. Something I did today is causing the salinity to drop -
   1. All I've done is fed the fish.
   2. I do wet skim but that would cause salinity to rise

 

[Dr. Reef]

wet skim will cause salinity to go down not up.
as you skim water with nasty's your skimmer is throwing out some saltwater into the drain and in order to replace that saltwater that left the system ATO will try to compensate with rodi water which has not salt in it. thus over time salinity will start to drop.

 

[burton14e7]

wet skim will cause salinity to go down not up.
as you skim water with nasty's your skimmer is throwing out some saltwater into the drain and in order to replace that saltwater that left the system ATO will try to compensate with rodi water which has not salt in it. thus over time salinity will start to drop.

Ah I misunderstood that. You think it would make it drop from 35 to 29 in one day randomly? It's been holding steady at 29 since last night, according to the probe that is. My digital refractometer is still saying 1.025 on the money.

 

[Dr. Reef]

depending on how much water is skimmed it is possible to shift salinity slightly but in order to drop from 1.026 to 1.021 it will take several gals of saltwater to be dumped/replaced by rodi water. unless it was a very small tank. my feeling is your probe needs calibration. if refrac is well calibrated with a standard salinity solution then i would trust it over the probe. (worse case if salinity standard is not available use rodi water and check the salinity)

 

[burton14e7]

If their probe requires calibration every 5 days it's being pulled and tossed, I already turned off the alerts. It's now down in the 28s according to the probe, but my Milwaukee is calibrated with 0.00 and 1.025 solution and it's still pulling 1.025 from the aquarium. My aquarium is only a 75 gallon and the skimmer is definitely not pulling gallons. I am kind of bummed to get this expensive new toy and have it not working within a week but I wanted to make sure I wasn't doing something completely wrong.

 

[burton14e7]

Here you can see where I set it up and calibrated it and it was stable until yesterday, and then the last 24 hours it continues to drop.

 

[kswan]

I would make sure there are no air bubbles trapped in the probe. It may help to re calibrate as well. I had issues at first too but has been rock solid for a year now.

 

[Dr. Reef]

I agree something is not right with the probe.

 

[Ditto]

Could microbubbles be interfering with the probe. Dip the probe fully underwater and do a slight angle with the end up to see if any bubbles escape the probe? Just a guess.

 

[scott11106]

check this out, i have the opposite issue

 

[burton14e7]

check this out, i have the opposite issue

Holy cow. Do you have any ideas why yours is going up?

I'm going to try the suggestions about the air bubbles.

 

[rlman41299]

When I had my salinity probe it drove me crazy for it keeps changing the reading after every few days and I have ATO so salinity does not fluctuate so bad. So I thought that my probe or the module itself was faulty but what was causing my fluctuations was the probe cable is sensitive to interference by my other electrical cables. It will be such a hassle for me to reroute the salinity cable so I just pulled it out and not used it again.

 

[burton14e7]

When I had my salinity probe it drove me crazy for it keeps changing the reading after every few days and I have ATO so salinity does not fluctuate so bad. So I thought that my probe or the module itself was faulty but what was causing my fluctuations was the probe cable is sensitive to interference by my other electrical cables. It will be such a hassle for me to reroute the salinity cable so I just pulled it out and not used it again.

I saw that in the calibration and setup guide by Apex so I routed the cable around the front in between the doors and the stand instead of through the back with all my other cables. I thought it was working since the readings were stable for a few days. I think I'm going to go your route and just pull the thing out. It doesn't seem to be worth the hassle since I have an ATO and alerts set up if it fills up too much or doesn't turn on at all.

 

[FFFishy]

Very likely that electrical interference is causing your inaccurate salinity readings. One method to check for electrical interference is to put the probe in a cup of tank water, away from your tank / sump. If the salinity reading appears to be accurate, you've found the problem.

 

[burton14e7]

Very likely that electrical interference is causing your inaccurate salinity readings. One method to check for electrical interference is to put the probe in a cup of tank water, away from your tank / sump. If the salinity reading appears to be accurate, you've found the problem.

Do you think just like 3-4 feet away? I don't think I can do anything more different than I am now to prohibit interference but it would be interesting to see if that's the cause. Personally what I'm more interested in is temp and PH but I was pumped to get a new toy and then bummed when everything wasn't working as intended. #firstworldproblems right? haha

 

[scott11106]

Do you think just like 3-4 feet away? I don't think I can do anything more different than I am now to prohibit interference but it would be interesting to see if that's the cause. Personally what I'm more interested in is temp and PH but I was pumped to get a new toy and then bummed when everything wasn't working as intended. #firstworldproblems right? haha

as long as the power is not running with the power and if you need to cross power cross at a 90 degree, at least that works for data cables like cat5. my water tests perfect at 1.026 or 35 all the time and i have a ATO and auto water change via DOS so it changes 5 gallons a day. i am going to take the probe out and put it back to see if bubbles and i will check power around other cables. i am still very pleased with the APEX and have faith i will work the kinks out. Last time i had a tank many years ago the only automation was dial timers so it is really great to have as much as we do.

just my two cents. i will check the bubbles tonight

 

[scott11106]

a quick update, i walked in to the sump, tapped on the probe rack and a bunch of bubbles flew out....might be something to it but i will monitor

 

[FFFishy]

Do you think just like 3-4 feet away? I don't think I can do anything more different than I am now to prohibit interference but it would be interesting to see if that's the cause. Personally what I'm more interested in is temp and PH but I was pumped to get a new toy and then bummed when everything wasn't working as intended. #firstworldproblems right? haha

The interference might be in tank or sump. In my case, I have a DC-powered Return Pump. Whenever it's running, the Salinity reading is not accurate. Turn-off that pump, and I get a stable and accurate Salinity reading within a minute.

 

[anit77]

Bubbles in the probe. Give it a good shake keeping it under water when you do so. Nothing violent, just shake it back and forth to dislodge any bubbles trapped in there. Then make sure there are no sources of bubbles in the area that the probe is placed.
If that doesn't get it to pop right back up there's something else going on.

Usually interference is a sudden drop when something comes on. Like T5's, the ballasts can cause a good bit of noise, especially lower quality ones. DC motors are another source. Again it's a sudden drop, not a slow prolonged decrease. That is a sign of bubbles in the probe.

A sudden increase would be from the probe clearing itself or a piece of equipment that's interfering with it turning off.

 

[anit77]

I installed a new 2016 model at the beginning of the month. The probes went online on the 6th.

Here's the begin graph and then the last day or two after 7 days. In the first one the jumps up are after me giving it a shake. Then after a week it stabilized. I keep my salinity at 1.025 or 33.3ppt.