Also - GFO if not properly fed oxygenated water from the skimmer outlet or similar can cause a low oxygen environment. No oxygen and the iron - phosphate binds will break resulting in free iron²,³(yes ferric oxide comes in both iron 2&3). In short non oxygenated Ferric oxide will break down to Iron which is blinded by DFO(Desferrioxamine) which is what inhibits growth in protozoa perkinsus by stealing the iron from the cell. Desferrioxamine is naturally occurring iron chelator produced by marine bacterium. DFO also prevents peroxynitrous and peroxynitric acid from forming from NO3 and free hydrogen ions in our high pH solution we call saltwater. Anyway, When you have the added amount of iron the naturally occurring DFO isn't enough to bind all the iron.
At the slow flow rate that we set our reactors. Typically if you were to test the water inside the reactor its or ORP will be low basically low oxygen environment. All this compounded can lead to readily available iron to the protozoa. Hence the reason behind some people having problems with clams when running GFO because DFO can't keep up and bind all the iron. Along with an initial stressor.
Basically running a ferric oxide in a reactor is a blessing and a curse.
When you bring it to the level of the clam. Iron and Desferrioxamine are always present right? So why doesn't everyone get pinched mantle? The naturally occurring DFO is enough to bind the iron from the protozoa cell to keep population in check in conjunction with the clams immune system. What happens if you mess with the clams immune system and have more iron?
Well when you first add fresh gfo some iron is leachd and also phates are bound quickly which can stress the clam causing its immune system to be susceptible to the protozoa that will then be able thriving off of the iron. Because of the iron content in the water exceeding the usability of corals, macro and all other life in the aquaria. The DFOs threshold can be peaked leaving an excess of free iron.
Also note when doing your regular water changes your also adding iron. But water changes should match the system inducing no stress to the clam, making it unsusceptible to the protozoa that it is always
keeping at bay via DFO and its Immune systems.
Ways to avoid this?
-Dont buy a clam lol jk
-dont run gfo when introducing a new clam.
- wait till the day before your normal water change and add the clam so the tank is low on iron. Then wait a week for it to adjust/get comfy so there won't be an iron introduction while its stressed/acclimating.
- start with small doses of gfo and work up every time you change it - and never shoot for zero or a rapid change
This post should probably be posted in the clam forum...think i may do that
Edited by Deckoz2302, 10 April 2012 - 08:26 AM.