Probe placement

mojoreef

mojoreef

Just a reefer
Was asking myself if the location I had my probes was the best (first chamber of sump). COncidering I have alot of equipment tied to those probes it could make a big difference. Well I mickmosed a set up and put the probes in the tank behind a little blind I made about 8 inches in depth in the tank.
Well thier were definately some changes. Biggest one was the ORP, it dropped almost a 100 points from 485 to 380, I would imagine from the airation caused by the drains. I have a ozone unit controlled by it, so big change.
Temp went up about a degree and balanced out with the other two temp devices I had. Temp is a big one two as it is the reference marker for both ph and orp.
last was the ph it went up by a full point and a half.

So lesson of the day, if you use probes, especially as controllers, pick you placement correctly.


MIke
 
mps9506

mps9506

Well-Known Member
Thanks for the info.
Why do you think the pH went up when you changed the probe placement?
 
mojoreef

mojoreef

Just a reefer
Well possible a few reasons, One is that the temp probe is used as a reference probe so when the temp changed so did the ph. then closer to vegitation?? maybe a bit more photo going on?? maybe the sump location had more organics?? hard to nail it down for sure


Mike
 
mps9506

mps9506

Well-Known Member
Positive nothing funky will go on due to interference from metal halide or vho bulbs/ballasts, etc?
 
mojoreef

mojoreef

Just a reefer
Yea Craig PH and orp are temperature compensated so it does come into play.

Dave thats always a good idea, lol

Mike I built a little probe holder out of black acrylic, the unit covers the probes (hiding them from view and light) as per interference, I would guess the interference would come from the ballasts not the bulbs right?? my ballasts are all in another location.
Also big point on putting the probes in the tank. Make sure that nothing can get to them (ie snail or crab) I can just see some snail making funny business with your orp probe while the ozone is pumping in.


Mike
 
V

VINA DEL MAR

Member
Probes should always be place right before the main circulation pump that's supplying all the water to the main tank, away from any water afluent like Ca,Alk,Limewater, ozone reactors.Your readings can be off by a lot if you dont.

VINA
 
mps9506

mps9506

Well-Known Member
I assumed you wouldn't have any interference problems with the MH bulbs, I just didn't know if perhaps VHO tubes might be more prone to causing problems. But sounds like you have it covered...
 
mojoreef

mojoreef

Just a reefer
Damm Boomer.....make me read all that again, lol
I still dont understand how having it in the sump or just prior to the return pump makes sence?? The water in the sump is not going to be the same as the tank water?? Its been cooled by the chiller, its been pumped up with cal and alk via a reactor or kalk mix, it has been airated to death by the skimmer. How does that work, or am I missing something???


Mike
 
Boomer

Boomer

Reef Sanctuary's Mr. Wizard
Ok maybe I should have expanded on it :D

Not just stuck in the sump but in a probe holder "feed line". The water enters from the a return line from the tank into a overflow tray/box unit, that sits higher in the sump. The return line is at one end of the tray. The return line enters the tray/box unit form the side. It is capped closed at the other end and a few holes are drilled in the return tube at the 6'O'Clock position. In the middle of the tray there is a recessed box. The top of the box is level with the tray floor. Then probes fit into a box shaped lid/cover, that covers the entire tray/box unit. The probes fit into a probe holder mounted on the lid, allowing them to hang down into the probe box. At the far end of the try is the overflow tube, which is mounted to the floor of the tray. Water from the return will rise up to this tube and then spills into the sump. The only water entering the tray is right from the tank. The water in the probe box is very slowly mixed by the passing water and rising water. The box lib should be made of black acrylic.
 
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mojoreef

mojoreef

Just a reefer
Ok that makes more sence, and to be honest I had a simular idea using a box. But then a few things came up. the water coming down the drain is going to be more airated from the long trip down (4 to 10 feet depending which drain) and then I thought its mostly going to be surface water no?? so it would have more organics, and would be alot warmer??

The holder I have is all black and sheilds from light, it is also suspended so no critter can get to it (well fish but I dont think they would). It is also taking readngs at about 6 to 8 inches deep in the tank. beyond more cleaning what are the down sides??


thanks bud


Mike
 
Boomer

Boomer

Reef Sanctuary's Mr. Wizard
Mike I just added some more detail as thought it wasn't enough. It is now EDIT
 
Boomer

Boomer

Reef Sanctuary's Mr. Wizard
and then I thought its mostly going to be surface water no?? so it would have more organics, and would be alot warmer??

Make its own small return line with a "J" tube a a couple of inches below water level. You can use a valve to control water flow from the J tube. Make sure it is not to far down so if power is lost it won't over fill the sump capacity and .........fed the floor with seawater :lol: I know big tank small sump it will fed the floor :lol: :lol:

If the surface is mixed properly there should be little differnce in organics or temp, pH or ORP
 
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