Phosphate or nitrogen

[ScottT1980]

I am still not convinced Mike...perhaps it is just ignorance on my part, but phosphate just doesn't scare me, nitrogenous wastes do...

Am I missing something? Have I been brainwashed?

[mojoreef]

Scottie thier were two question posed in this thread. One was in regards to limiting factors and the other was concerns regarding.
On the limiting factors I was trying to show that nitrogen products are not truely limiting a they can be made up by cyanos and other bacterial form. Phosphates can not be made up in our tanks they can only be added.
On the scarest thinging. Yes when comparing Nitrogen products such as ammonia/nitrate/nitrites to P and its various forms nitrogen is much more of a toxic component. BUT, lol when you look at them as they are present with in our reef tanks it becomes a different story. If you run a BB or a DSB type system with LR you are going to have alot of bacterial controls on nitrogen based elements, but none really beyond algae to control P.
Now when you look at these components as they relate to our corals you see the following. Corals absorb nitrogen based products directly through thier tissue and use it to form tissues and complete cellular reproduction. So low levels are actually good for you corals. But with P thier are a number of derogatory reactions with it.

Anyway that was kinda where I was trying to originally trying to go with this.

Mike

[ScottT1980]

I'm with you, I think a bit of tunnel vision was my problem...

[Maxx]

So Mike,
On a smaller system, (say a BB 58 gallon w/a good flow and and a oversized skimmer... ), what ways/methods of controlling phosphate in the tank would you reccomend?
I know about rinsing all foods in RO/DI water and discarding the water, and I am now planning on running the phosban reactor, (cheaper for me and most likely more than suffiecient for my needs.), but what other methods would you suggest for controlling phosphates in the system.
I'm very interested in learning about all of this since I do plan on upgrading to a much larger tank in the future, and I assume that controlling PO4 in the smaller tank will be slightly easier to manage, because if I understand correctly, PO4 has to be introduced into the tank.
Thanks,
Nick

[Curtswearing]

I think that even if you don't introduce it, it's gonna get introduced anyway. I think that we already have P in our systems from the get-go. If you could find a salt mix that was 100% Phosphate free, and verified that your RO/DI water was absolutely Phosphate free and put this salt mixture into your tank it wouldn't take very long at all for an airborne bacterium containing organic Phosphate to land in it. This bacterium would eventually die so we would now have our first instance of inorganic Phosphate as well.

I have always liked the following slideshow. It's not geared for reeftanks but it shows things on a global scale. It also describes briefly the different forms of P like Boomer and Mike were discussing. If you read carefully, it also discusses how Ammonium can keep recycling as well. (For those who want to read every slide, it also describes why Iron-based Phosphate removers are efficient).

Slideshow on Marine Nutrients

I looked at my original post and I want to define a word I used. I know I'm describing this wrong but this is how I think of it. I used the word "limiting". The first time I saw this word on the boards, I was . I simply didn't know what it meant. To me the word limiting means "if ya don't have it, you're gonna die because it is a requirement to keep living".

The attached pic is also not reef tank related by I like all the pretty circles.....just kidding.

I'll see if I can find a decent reef-related link about this.

Obviously, being careful about the input is important for Phosphate maintenance. We can also use macroalgaes and skimming for removal. We especially want to get rid of detritus before it breaks down and this can be accomplished in numerous ways.

[Brucey]

Hey Curt . . . . you knocked the nice little pic up quickly mate. :-)

I control phosphates by . . . . feeding the fish only what they will eat in a few minutes, RO/DI, RowaPhos Filter, Oversized skimmer, BB tank, 10xwater flow and 30% water change once a month. It's an ever increasing battle and I still get small amounts of Microalgae growing that I guess mean their are phosphates available for them to feed on ????
Brucey

[mojoreef]

Well Nick thats a question with a long tale, lol. For me P is the amin battle i fight, I am not to worried about nirtogen as thier are many checks in place. Know that one must introduce P into the tank in order for it to be thier aides in the battle. Yes as Curt says you will never eliminate it but in reallity you never want to as it is an important element present in all forms of life. What we are looking for is the line that seperates normal and excess. Excess can be determined by an ammount of inorganic P (PO4).
Foods are usually the way most enter the tank
Salt mixes will either have P or N in them in excess, so I avoid the wones with P (tropic Marin is a biggie for P)
Addivtives are another big one, most additive labeld as bio mean they use sugars as carriers, and in most cases contain large ammounts of P. Also the use of CC or argonite sand in reactors release alot.
Allowing a sand bed to go anaerobic will free up a ton of bound up P in the sand and make it available in the tank.

Ok so thier are a few things you can do to control input.
Now on controling the export.
In our tanks your going to find P in a few places.
> first place is going to be bound up in sand or LR. For this I try to keep both of these well aerobic, this keeps the ph up and does not allow for it to be unbound if if it does it is quickly rebound. This is a tough battle with deeper sand beds though.
>P is always going to be assocated with food and waste. So feeding only what the fish will eat and then makeing sure that checks are inplace to remove the excess is critical. So all detritus and excess for must be removed as best as you can. Skimmers running wet, occasional filter sock and so on are very effective in remove this excess.
>next would be the exports of critters that bind P with in their matrix. Bacteria will envelop and multiply detritus and waste, they will also create a biofilm of organics that they use to reduce the above,these organics are loaded with P also, so in getting rid of the extra food, waste and detritus in general we are exporting both organic and inorganic P, best tool for battling it.
> last way is the excess inorganic P that is available in the water column. Once you system reaches a point where it can no longer bind up any organic P, P will then remain available in the form of PO4, this is what our test kits can test for. So if you have a reading of PO4 you know your tank is saturated organically with P. For this group I use a P remover such as rowa or phosan. any water that passes through it will have the PO4 removed from the system.

hope it helps


Mike

[ScottT1980]

Does P only inhibit SPS/LPS coral growth (being that it is a cation that can compete with Ca) or is there another mechanism by which it can inhibit all coral growth? I did some lit. searches and could not find anything.

[mojoreef]

Scottie it does play a higher role in screwing up LPS and SPS as it screws with calcium content, also it screws with fertilizing the zoox in corals, which takes controls that the corals has in its ability to control populations of its zoox population. This usually leads to an over population of zoox in corals (which can be visualy seen by the coral turning brown, the color of zoox).
In soft corals, they demand for P and N is haigher as they have more tissue to support and grow and p and N through absorbtion is a intrical part. But in saying that excess of anything is key, so one must try to keep these levels close to natural levels in the corals biotype setting in the wild.
In the wild thier is a constant battle between algae and corals, they are competitors for nutrients and other food sources. In most cases if you see algaes you dont see alot of corals . Thier are however subtle differences in feeding and absorbtion rates between corals and algae, on coral reefs it is skewed to that of the corals, tus very little algae with the exception of calcerious forms.
Scott in my line of thinking it is all about the enviroment you create (water quality) if you create a condition that is skewed towards the liking of corals you will create an atmosphere inwhich they can strive and be the dominant species. If you create one that allows for high nutrient content and eutrophication then you have skewed it towards the liking of algae and that species will become dominat.

boy I am not sure if I answered your question or not , lol so let me know.



Mike

[ScottT1980]

boy I am not sure if I answered your question or not , lol so let me know.

Yes, perfectly...I forgot about the continual zoox dynamic, makes complete sense to me...

[ScottT1980]

Actually, I must ammend my earlier comment about P being a cation (it is but I meant PO4), it must have been a bit earlier and the years of general chem are long gone.

Phosphate is an anion, phosphrous is a cation. I would imagine that calcium binding to PO4 could be the cause for concern...

Anyway, just wanted to recognize my mistake

Take er easy
Scott T.

[corvettephreek]

yup... uh-huh... i agree.... phosphates are my main concern, I didnt even know about nitrogen until now... I guess Ill have to check it tonight when I get home....

[fishhead]

The relative number of nitrates to phosphates in an out of control tank can be at least around 1:50, so there are alot more of the less harmful nitrates present to feast on to begin with