I'm looking for opinions of what might be causing low ORP in my tank. The tank is 13mo's old, my prior tank would run ORP in the ~400 range, my current set up is 250ish... The tank is a 300G SPS dominant system, dreambox sump w/ a fleece roller (rolls the fleece every 6hrs), a bubble king deluxe 200 skimmer, 2 red dragon rd3's for returns (maxed out), 2 pentair UV's on the system (on for 8hrs / day), with 3 MP40's in the tank running at 60-75%, 5G AWC every night, carx + alk/cal/mag dosing. Parameters are stable, 8dkh, 400cal, 1275mag, 1.025g. I know folks will say don't read into ORP, use it as a fluctuation indicator, but I'd still like thoughts on what might be driving a low regular reading on the tank.
ORP
- Thread starter cklayko
- Start date
It sure does. I would love to see a build thread.
build thread is here... 280g New Build
2 sand sifting stars, one sand sifting goby and a bunch of hermit crabs
here you go: 280g New Build
This is what's lowering your ORP. New salt water always has low ORP. Additives like Fuel, Chaetogro also lower ORP.
The dip on the right is a water change on my system.
that makes sense, but I also did 5G AWC on my old tank and it didn't have this level of impact. Could it be I need to tune my skimmer differently?
I think assuming 400 ORP is 'better' than 250 is the problem. There's so many factors that effect the resultant value that the value itself is less relevant than the trends you might observe. My ORP was normally 200-250 but I started dosing ammonia as a nitrogen source (because of zero nitrates). This caused my ORP to rise to 400 for several months and since has settled in that 300-350 range. According to the article I'll post below, RHF says ammonia is a reducer and should lower ORP. Since my ORP rose, is the ammonia food for good guys or poison for bad guys or something else? It's complicated and I'll except just not knowing.
Anyway, as for skimming, oxygen definitely raises ORP so if you can get more air going that's the effect you should see.
ORP and the Reef Aquarium
