View Full Version : Apex Classic erratic temp readings (but only during certain time of day)

02/23/2017, 04:10 PM
I posted this in the Neptune forums also earlier today. No replies as of yet.
Figured posting here too can't hurt.

Some background info for ya first. About 2 weeks ago I constructed a new retro light rack consisting of 3- 250w halides and 4 single bulb T5 actinic units. The T5 units are fully self contained Reef Brights and the halides are 3 Luxcore ballasts. Everything is new. I basically replaced a light rack I've had on my system for 5+ years with one a bit larger for more coverage. All aluminum frame construction.

Temp readings started going haywire when I installed the new lights. At first I didn't make the connection. My temp probe was about 7 years old so I figured it just crapped out on me. Ordered 2 new ones. Replaced the old one and thing worked fine again but only for a couple days. Then erratic readings again.

Over the past several days I've noticed a pattern. My halides are set to come on daily at 12:30pm and shut off at 10:30pm. As soon as they turn on the temp reading instantly drops to about 65 degrees. When they shut off at 10:30 temp readout returns to normal at roughly 77. T5's on or off don't effect readings. So I'm thinking RF interference right? But everything related to the halides are several feet away from both the brain controller and temp probe/wire. Puzzling

But here's the kicker... I also noticed that whenever I turn off the return pump for feedings or whatever the temp reading drops to ~ 25 degrees. When return pump is turned back on the reading climbs back up to about 65 again. At 10:30pm when halides go off temp readouts return to normal and remain normal all night long until next day when halides come back on. any ideas? I have since ordered and received a new control module. Worst case scenario I'll have a backup now. I have tens of thousands invested and am not willing to lose it over a $300 part.

In the pic below the flat line is over night consistency. The first dip is halide on time and the 2 deep dips are the 2 10min daily feedings. Feb 16-18 is when I installed the new probe.

Any thoughts/ ideas are welcome. Thanks

http://i101.photobucket.com/albums/m53/chirocato/07AB7049-6FF9-4FEE-A619-CC9D214B2437_zps9frsacji.png (http://s101.photobucket.com/user/chirocato/media/07AB7049-6FF9-4FEE-A619-CC9D214B2437_zps9frsacji.png.html)

02/25/2017, 10:27 AM
Almost 80 views and no one has any thoughts on this. Not a good sign. lol

On another note...
Played around a bit last night. Found out that if halides are off I can shut off return pump to feed without any effect on the temp readouts. But when halides are still on and I shut off return pump it makes temp readouts even wackier. Bizarre. Some how some way I'm thinking it's gotta be the halides causing the issue.

02/25/2017, 07:02 PM
I viewed it last night, but didn't comment. Seems like an obvious electrical interference issue, which you seem to be leaning towards also. Time to start troubleshooting, which is hard to do over the interwebs! :)

02/25/2017, 10:43 PM
Yeah, That was my view also.
I think you are thinking exactly like I would and have come to the conclusion it is most likely interference from your new gear.
Only thing I can possibly suggest is that you are getting a EMF build up in the tank itself? But again you will need to test all your systems to see which is causing the problem.
Hard to measure your actual voltage on the temp probe as it is pretty small. But maybe get a logging type voltage meter and put a lead in the tank and the other to earth to see if and what potential is there. Then monitor it while you disconnect turn on/off etc.
Not sure what type of Halide components you have, but my last set had cheap Chinese ballasts in them. It drew double the current and had crazy interference with a lot of items. (Did not notice your problem).
You could be getting feed back into the mains also. But I would expect your Apex power supply to isolate that prior to feeding it to the apex.

02/26/2017, 08:00 AM
I think I'd open a ticket with support. They've probably seen weirdness like this before and can get you started down the right troubleshooting path.

04/14/2017, 05:14 PM
I had a similar issue with a Luxcore MH ballast. When it was on, my return pump (ecotech vectra) and Gyre ran at 1/2 speed, and it caused my ph readings to jump. Everything was on my apex classic

04/15/2017, 07:16 AM
Some high powered ballast can cause interference, it could be as easy as running the temp probe wire by itself not touching any other wires, or segregating the ballasts as far away as possible from the apex and probes.