Might be the dumbest question of the day

[jdloftness]

I am trying very hard to understand everything that goes into good water parameters, but it's almost like a foreign language that I can't completely grasp.

I have always fought high PO4, but recently added a phosphate reducer to my GFO reactor and now my Hanna reads 0.00. I know that's not good for my LPS corals either, so here's the qualifying question:

Do I dose to increase phosphates, or do I try to reduce the phos-ban in my reactor?

Thanks in advance for not calling me an idiot, and for any advice you might offer.

 

[doubleshot00]

Remove the reactor and re-test 24 hours later to see where your at. Comtrol your feedings to. Fyi test before you feed.

 

[NowGlazeIT]

Remove or cut off the reactor till your phosphates need to come down again. Ideally you want to run just enough media to regulate your phosphates to your desired level

 

[doubleshot00]

Im curious how much gfo you added to make it bottom out so quickly.

 

[G Santana]

Not a stupid question, but rather the old P04 dilemma, one many of us have had to face.
Before my tank hit the years mark I too played the whack a P04 game, I would get it low and then it dipped to Zero and then back.
I stopped worrying about it when I got it below 1 and then I chased lower nitrates and dosed vodka and then I hit the under 10 N03 and stable P04 between .03 and .06.

I would just feed a little more and try to get the number up that way, as long as you don't have an algae bloom going then your tank really is at zero P04.

Good luck!

 

[ZombieEngineer]

Stop reactor and recheck tomorrow. If still 0 retry the next day. If still zero after that, I would dose enough to get you to 0.03 staying at 0 risks dinos.

Once your reading starts climbing above 0.05, start the reactor back up with maybe 1/4 of what you put in this time and monitor. Use trial and error until you find an amount of phosban that more or less keeps your phosphates stable.

 

[vetteguy53081]

The reducer is the issue why you achieved Zero especially if GFO. Feed your tank as normal and as suggested with reactor off, you should see increase gradually.
I use ChemiPure Blue to keep my po4 in check and in extreme cases ChemiPure elite for po4 control
You do want to get this up a little as zero can promote or trigger Dinoflagellates

 

[theMeat]

Would double check your readings with another test kit. Maybe your lfs could do it for ya

 

[dthom]

Just curious about how high was your P04 before?
Were you having issues with algae and this was why you were trying to get it down?

 

[PatW]

The test you are using is pretty important. The most sensitive test on the market is the Hanna ULR phosphorous tester. Even with that test, the suggested phosphate level for reef aquariums is on the low range of its sensitivity. I run chaeto in a reactor. I typically get a 0 on phosphate. But I have a large system with tangs that poop out quite a bit of nori. I add a bit of phosphate when I get 0. That and the poop seems to keep everything happy and I have an SPS dominant system but I also have euphylla, fa via, and a cans an they do fine (sp corrected by Apple).

The problem with GFO is it strips out phosphate pretty fast. I had a blip in phosphate and I ran 2 tbs of GFO for a 300 gallon system and that took it right down. I removed it right after the decrease. Now, a much smaller system may require more GFO because phosphate can get absorbed into the rock work and slowly leach out to be taken out by GFO.

 

[JCM]

This is why GFO gets a bad reputation. It's extremely good at removing po4 and needs to be used cautiously. When used correctly, it's great.

Take the reactor offline and continue to feed normally. Your rock will leach phosphate to reach an equilibrium with the water.