What to do about sustained phosphate and nitrate problems?

[jaddc]

I'd normally agree with you on the biopellets/GFO in theory, Dave.  But I've noticed that they don't really do much for phosphate compared to nitrate.  Even beyond the redfield ratio which should be roughly 16:1 nitrate:phosphate.  My experience is that they work wonders for nitrates, but a little GFO for phosphates is still needed.  But that's based on a sample size of 2 systems, so highly anecdotal.  If you have nitrates at 20ppm and phosphates under 1ppm, you'd think PO4 would be the limiting factor and nitrates wouldn't fall more than 16ppm.  But they will (IME), and phosphates won't change all that much.  Add a little GFO and you should get both down to very low levels.

 

 

I'd guess that is because nitrogen is always bio-available thanks to the bacteria. 

 

The problem is that there is a natural buildup of inorganic phosphorous compounds in the rock. The phosphate content of your rocks depends on the source of the rock. If you "cook" the rock, you get rid of the organic phosphorous, but the inorganic phosphorous is still there. I believe a common form is apatite which is calcium phosphate. It stays there until it redissolves in the water (I think that is quite slow -- not sure) or bacteria or fungus consume the inorganic phosphate and then release bioconverted organic phosphate into the water.

 

That's why I usually recommend to not run both at the same time. Run the bio-export for soluble N and P until the levels stop decreasing and level out. This sets the export ratio equal to the input ratio.

 

What I have done successfully in the past is use chemical filtration to remove the excess. BUT as soon as the excess is gone, I stopped the chemical filtration before the N:P ratio will be out of whack again and the battle restarts.

[marinap]

I am leaning toward taking everything apart and starting over….

That's what I would do. Sorry to hear about all the troubles.

[ctenophore]

I'd guess that is because nitrogen is always bio-available thanks to the bacteria. 

 

The problem is that there is a natural buildup of inorganic phosphorous compounds in the rock. The phosphate content of your rocks depends on the source of the rock. If you "cook" the rock, you get rid of the organic phosphorous, but the inorganic phosphorous is still there. I believe a common form is apatite which is calcium phosphate. It stays there until it redissolves in the water (I think that is quite slow -- not sure) or bacteria or fungus consume the inorganic phosphate and then release bioconverted organic phosphate into the water.

 

That's why I usually recommend to not run both at the same time. Run the bio-export for soluble N and P until the levels stop decreasing and level out. This sets the export ratio equal to the input ratio.

 

What I have done successfully in the past is use chemical filtration to remove the excess. BUT as soon as the excess is gone, I stopped the chemical filtration before the N:P ratio will be out of whack again and the battle restarts.

Makes sense.  Thanks for the insight.  So I wonder, which is worse- "dry" rock full of inorganic phosphate (if they mine it out of FL then I know it is; the place is basically one big phosphate mine) or "old" liverock, which may have absorbed organic phosphate.

 

Laura, Marina's advice may be best- start it over with a different approach to substrate.  If it's a packed SPS tank you want, then you might consider those ceramic eco sculptures that Marcos got.  Or do the cheap approach that I did- build a PVC frame in the shape you want (heat gun to bend), then cover it with epoxy/sand/rubble mix to blend it in and give texture.  My SPS are loving it. Plenty of light and flow from all sides, and mounting the corals is very easy.  Not much space for algae to grow or detritus to settle, but it looks kind of weird while the colonies grow out.

[jaddc]

Makes sense.  Thanks for the insight.  So I wonder, which is worse- "dry" rock full of inorganic phosphate (if they mine it out of FL then I know it is; the place is basically one big phosphate mine) or "old" liverock, which may have absorbed organic phosphate.

 

Laura, Marina's advice may be best- start it over with a different approach to substrate.  If it's a packed SPS tank you want, then you might consider those ceramic eco sculptures that Marcos got.  Or do the cheap approach that I did- build a PVC frame in the shape you want (heat gun to bend), then cover it with epoxy/sand/rubble mix to blend it in and give texture.  My SPS are loving it. Plenty of light and flow from all sides, and mounting the corals is very easy.  Not much space for algae to grow or detritus to settle, but it looks kind of weird while the colonies grow out.

 

 

Hmmm. Good question. I agree about the Fl rock -- mine definitely upsets the N:P ratio. I had it under control and then I re-scaped a while back when I moved and cut some of my rock to size. My phosphate problem started all over again. Took a couple months of aggressive GFO, but all is good now.

 

Basically any rock near river/farm run off will be a phosphate sink.  Reef rock from reefs (which I suppose is not the environmentally friendly way to go) would be best since phosphate levels are lower. 

[goodreeef]

Makes sense.  Thanks for the insight.  So I wonder, which is worse- "dry" rock full of inorganic phosphate (if they mine it out of FL then I know it is; the place is basically one big phosphate mine) or "old" liverock, which may have absorbed organic phosphate.

 

Laura, Marina's advice may be best- start it over with a different approach to substrate.  If it's a packed SPS tank you want, then you might consider those ceramic eco sculptures that Marcos got.  Or do the cheap approach that I did- build a PVC frame in the shape you want (heat gun to bend), then cover it with epoxy/sand/rubble mix to blend it in and give texture.  My SPS are loving it. Plenty of light and flow from all sides, and mounting the corals is very easy.  Not much space for algae to grow or detritus to settle, but it looks kind of weird while the colonies grow

 

 

I am interested in your  /epoxy/sand/rubble pvc structure........ how exactly did you do this? Using a heat gun to mold a structure , I understand, its the epoxing sand  to it , that i am trying to grasp. did you use argonite, what grain size,etc?

[Sharkey18]

Wow. Good info. 

 

It seems that doing a thorough cleaning has helped.  After I removed a lot of rock and added two movable power heads to blow off the rock ( i move them around a lot)  I tested the Phosphate and it was .15.   Today, after a few days with less rock and less detritus, phosphates are down to .10 . I know its still high but I haven't gotten it down to .1 in 6 months and AND i stopped dosing the Lanthanum Chloride.  I decided to just simplify everything and took all my reactors off line. 

 

I am going to continue to increase my water changes and clean out the tank. I am AMAZED at how much CRAP was hiding in and under the rock. Its quite gross.  I still have a fair amount of detritus cleanup to do so hopefully that will continue to lower the phosphates. 

 

Is it possible that my issue could be mostly from crap accumulation? 

 

The rock that I removed, and is in a 50g drum has increasing phosphates. The day after I pulled them from the tank and put them in there the PO4 was .05. Today it is .1  Not a huge increase but I will be keeping an eye on it. I have not done a water change there yet…. Making this much water takes forever and I am using most of my water production to do water changes on the tank…. 

 

I so appreciate the help I have gotten here. Such great ideas. I have a lot of work to do but at least now I have some things to work on:

 

#1: Get a better more productive refugium

#2: Add a xenia tank, attached but separate from the main tank.  Is there a type of xenia that works better than others? 

#3: Eventually add bioballs or dosing. 

 

I love having a plan. 

[wade]

 

 

 Is it possible that my issue could be mostly from crap accumulation?

 

Yes, although that crap comes from somewhere, so once you are cleaned up, be sure to watch feeding volumes and keep removal high.

 

As for your plan, I wouldn't bother adding a xenia tank unless you really want to. If you really want to try that route, just place them on the glass away from any rocks and let them spread up the glass.  It is very easy to scrape them free from glass or acrylic.  Just don't let them run into your rock pile.  

 

I'd also remind you that adding bioload (any kind, xenia or macroalgae) will increase bioligical production - which means various things get added to and taken away from water, including more organic materials.  Personally, I'd crank up the skimming, make sure to feed well and keep up with any detritus removal, and let the tank stabilize that way first.

 

Glad to hear you are seeing a difference though.

[Sharkey18]

Hey Justin, I just read through your build thread. Besides having some hilarious pics…. the tank looks great. 

 

Since I am essentially starting over, I will probably re-arrange my rock into some time of pillar like structures. This way I can create better flow to avoid the massive detritus accumulation that I have.  

 

I did not see ceramic structures on Marco site? Are they from somewhere else? 

[sen5241b]

If you are over-stocked then the only solution may be to take out some fish!

 

I have kept phosphates at zero with cheato in a fuge 10% the size of my tank. Macro-algae cannot do its job unless you have strong flow (200 to 300gph) and strong light! I am amazed at how little flow and light some people have over their fuges. I suggest multiple bulbs in case one goes out while you are out of town.

[gmerek2]

Surely no one on wamas has an overstocked tank that's just nonsense. my fuge is a little bigger than 15% people also laugh at my 6LED lights that make the chaeto have to get a basketball trimmed out once a week. The LEDs are strong 3watts per bulb and I believe that penetration is important. My chaeto doesn't have much flow. I had a nitrate and phosphate problem. The fuge helped a lot with the 80ppm nitrates now undetectable. Along with larger skimmer and no one else believes me but I think extra lighting helped Lower the nitrates a little. Only 3/4 my tank was lit. Phospates for me has to be controlled with GFO for now. I tried discontinuing but some GHA started to come back. I'm going to continue running GFO until rocks are done leaching. I like your plan. I think it will work you won't see the numbers right away but they will continually lower. I think fish crap is just a situation that causes most of our crappy problems in this hobby.

[ctenophore]

Hey Justin, I just read through your build thread. Besides having some hilarious pics…. the tank looks great. 

 

Since I am essentially starting over, I will probably re-arrange my rock into some time of pillar like structures. This way I can create better flow to avoid the massive detritus accumulation that I have.  

 

I did not see ceramic structures on Marco site? Are they from somewhere else? 

No, I mean Marco's (monkiboy) got some nice ones.  This: http://cerameco.com/gallery/vida-rock-standard-shapes/

 

I will dig up some pics of my poor mans cerameco

[Sharkey18]

Awesome. Just spent half the day reading through Marco's build. WOW!  and yeah, I can't afford that stuff. 

 

The good news is I think things are improving.

 

Rob was awesome and stopped by yesterday to take a look around. He also tested my water with his Salifert kits and everything actually checked out pretty well! Who would have guessed? Nitrates are still around 10, but phosphate was barely detectable and everything else was within normal range!

 

Some of the corals seem to be looking better but that could just be my hopeful brain playing tricks on me. 

 

I think the problem was actually building for a very long time and the result of stacked mistakes. I was over-feeding, not feeding the right stuff, my rock work was too dense, my refugium is under sized and I never turned the refugium lights off.

 

I also messed things up further trying to fix them. I started dosing vinegar, but obviously wasn't careful enough because most of my macro died. The waste from the rotting macro probably added to the problem as well as lowering my nutrient removal abilities. Not sure why vinegar dosing would kill the marco but the two events were pretty closely linked. 

 

I switched foods and stopped over feeding WEEKS ago. What I did not realize at the time was how LONG it was going to take to remove all of the excess nutrients that had built up.  I foolishly thought things would get better soon after I adjusted my behavior. Two things wrong with that.  1) Once I polluted the system I I needed to start an active recovery process, rather than just wait for things to get better. 2) I'm dealing with a LIVE SYSTEM. Pollute the system and it doesn't just spontaneously recover in a week. It is going to take a few MONTHS for things to get back to where I want them.   

 

I think I was actually on the right track before my desperate plea for help, but things would have never gotten much better without all of the great advice I got here. The turning point (I hope) was removing a significant amount of rock so that I could actively remove the debris that was stuck in and under the rock from when I was overfeeding. I certainly hope so. 

 

Thanks again for all of the help.