Appropriate nitrate levels for different corals.

could it be possibe that blowing the perimeter of the sand bed is stiring the nitrates in the sand bed?  

Matthew wrote: Which part didn't people understand? :/   I guess no one has read all the posts???   He mentioned Hydno as SPS and was wondering how their parameters were different. In the very first post, they are not a typical SPS.   The article linked about halfway down page one contains some very erroneous information. I then relinked it and attempted to correct the info. The idea that fish DON'T excrete ammonia??????????? NOT TRUE   Or nevermind...

Jake Pehrson wrote: I think the above recommendation are pretty good. -I am not sure if you mentioned the sand depth in you refugium.  I would just add more sand.  The smaller the grain size the less you will need. -Do large water changes until your nitrates are below 20 -DIY foods like "Curtis' frozen concoction" are great, but the problem is that it will add a lot of nutrients to the water that will not be consumed easily.  Get a strainer or some cheese cloth and rinse the food before adding it to your aquarium. -up your skimming if possible -run carbon

As far as the food goes...If you are battling nitrates or ammonia issues I would stop feeding my food all together until it is under control. I dont think that straining it is going to help that much and whatever it does remove will likely be what the corals eat. I would just feed something like frozen mysis or something for a while. No flake or pellet foods either, they wont help anything when it comes to nitrates. I agree with what has been said above, run carbon. If you can hook up a RDSB that would add a TON of biological filtration. You could also potentially look into a sulfer dinitrifier. I would call Eric at Marine Aquatics if you want to find out more about one of those or get one made.


Edited by downhill_biker - June 26 2010 at 9:06am

Well said, Matthew.

This thread has advanced to more than what fishoutawater was originally asking. I wonder if this was a question posed not so much for his enlightenment but more for general discussion?

fishoutawater wrote: I know some are not bothered by them as much as others, softies, most of the lps. But what is the highest level tolerated by sps like montis, acros, birdnests, millie's. And do hydnophora do better with very low nitrates? My tank has never tested below 20, and sometimes as high as 50, I am guessing this is the reason why not all of my pieces are thriving.

I've found that even tanks with near zero Nitrates cannot grow some things that other tanks can. The reason why seems to simply be the differences in the way the tanks are set up filtration-wise and the tankmates. Some coral get along with their neighbors and others don't.
Since GSP don't do well, have you tried green Briarium? It has a similar look with green polyps covering surfaces.

Monti plates are easy. Digitata is really easy - I started with that before getting into other demanding SPS. Benefit is they grow REALLY fast. Milli's have always been easier for me but your mileage may vary.

If the sandbed is producing bubbles, isn't that a sign of denitrification?

I agree that M.digitata is typically the easiest fastest growing SPS, yet some tanks don't grow it as well as Acropora. One of the hardiest Acro is the Green Slimer (A. yongei). There should be plenty of that here in the club.

You are right. The bubbles can be an indication of denitrificaton. They can also be the result of simple oxygen production via photosynthesis of the algae at the edge of the glass.

Yes, the improved look of the coral and anemones is because of cleaner water due to reduced N compounds. As you have seen, the reduction of feeding can allow the biological filtration to quickly eat up the extra nutrients.

My guess, just from the pics is that the sand is being disturbed too often. Sounds like you are more concerned about black sand than you need to be. Dirty sand is actually healthy sand enabling good biofiltration.

That frag of Hydnophora looks irritated. It should be all bushy. (If you hadn't told us it was Hydno, I would have guessed it was a green Sinularia.) It is sitting in a soup of chemicals produced by the field of green and purple polyps it is living amongst. I would move it to a new place. You are using AC, right?

Edited by Mark Peterson - June 28 2010 at 9:49am

Bubbles that come from the deep and leave a little trail as they rise up the glass are definitely Nitrogen. It's my understanding that the other compound that forms in the process is water; hard to see that one.

I may take you up on your offer to use your test kit Jeff, some days I look at those pics and think 10?, then I look at the other pic and think 50?, irritating.

Edited by fishoutawater - June 28 2010 at 11:38pm

There that was great. Thanks for posting a pic of the Refugium.

Okay I went back and read all that you said about this situation. Here is what is I believe is happening in this system.

- There is not enough LS biofiltration. Partly because of the sand in the main display being disturbed too often and partly because there is no sand in the Refugium.

- I'm guessing that the algae in the Refugium is not being harvested, probably because it is not growing that well. The yellow, dieing and dissolving algae is putting nutrients back into the Refugium where the remaining algae is absorbing those N compounds just to stay alive. Caulerpa fronds are typically not more than two feet long. In ideal conditions Caulerpa multiplies by branching.

- Just for fun, I would test a sample of the water directly from the outlet of the Refugium. My guess is that the Nitrates will show closer to zero there. If not, this blows my whole theory.

- There needs to be more flow through the Refugium. This would make better use of the Refugium by feeding the 50ppm Nitrates to the Caulerpa and the new sand bed. There is no need to build in an RDSB if the present Refugium is put to better use.

Of course I could be wrong about this.