Help! Barebottom / SPS Dying!

[fishdoc11]

Chris, I read that thread (it's been a while), but as I remember, those people who saw immediate results removed the whole pump and replaced it completely with another pump.

I very much agree it could be the pump as a whole or it could be the screws. IMO it just goes against common sense to put metal of any kind in a closed saltwater environment. Reefs on ships etc....is a totally different thing. How many billion gallons a day water change takes place in such a circumstance? Also in my tank most corals were not effected so you can't really make blanket statements saying iron won't hurt corals, it may not hurt some corals but all corals is stretching it IMO(FWIW IMO iron and aluminum based PO4 removers are bad for a tank also). Putting nails in a reef tank.....well we used to think 4 40 watt bulbs was a "well lit tank":lol: Please excuse the rant but it really irks me when people say things can't happen when they really have no idea if they can or not. That may not be their experience but saying it just ain't so is not accurate. Saying IMO that probably isn't the case or saying I have used such and such for x number of years and never had that problem is more responsible IMO.
When I ask if someone has a mag(or RIO) pump or metal of any kind in their tank I am merely seeking to eliminate one of many many possibilities. There are a multitude of things that can wrong in a reef tank and many times causes are never found. IMO if you can eliminate POSSIBLE causes one by one you can slowly narrow your focus and hopefully come to some sort of conclusion.

Chris

 

[Greg Hiller]

Rust bits fall into one of my prop tanks all the time with no problems. I use rusty pliers for fragging corals in the tank all the time. I think a pit of rust in a tank (IME/IMO) is really not a big deal. FWIW, the Mag pumps are junk anyway and rarely last more than a year or two.

 

[RichConley]

I agree Greg. I was talking to Bec earlier this week (her tank is rediculous) and she doses iron, so Fe is not the issue. Those screws on the mags may not actually be SS. Who knows, they could have some copper content in them.

I REALLY REALLY REALLY dont think the screws are the issue...but nylon screws are like $1. If you're having trouble, replace them. It probably wont fix anything, but it narrows the problem down a little.

 

[coralnut99]

I could be wrong, but I think it's only the Mag9.5 that comes with stainless screws. If nylon screws are tough to come by, you may be able to get stainless ones from Danner.

I've been giving this some thought, and I'll admit that there's at least a possibility that the screws are a problem. For exactly the reason RichConley put out as a possibilty:copper. Since these screws are only plated, who knows how consistent the plating process is for such a cheap component. Bad plating could be leaching something other than iron, that in minute levels could be a real problem. Most of the screws on the four Mags I use are rusted to some extent, so I suppose there's at least some luck involved.

 

[drock59]

update?

 

[REEF-DADDY]

I had the same problem, I ramped up my feeding and cut my photo period is half. Problem solved!

 

[solbby]

I am the original person who observed that rusted Magdrive screws in my tank were affecting my SPS. While I would be the first to admit that many things could cause the problems observed in jb32172 tank, my tank's problem was only discovered after months of trial and error in trying to identify the cause behind my tanks slow downfall.

I fail to understand why the idea of rust present in an SPS tank is dismissed as irrelevent to the success and survival of SPS when the scientific literature clearly cites the potential problem associated with heavy metal toxicity. But I guess the observations by some reefers that say " I have rusted screws in my tank and I see no problems" is good enough. Well all I can say is this warning "give it some time".

Anyway I do not wish to derail this thread (I am not getting into another fruitless conversation here on RC) and I hope that the intial reefers tank is bouncing back.

<a href=showthread.php?s=&postid=5921370#post5921370 target=_blank>Originally posted</a> by solbby
Harland and Brown did a study looking at the addition of adding iron at a concentration of 10 ug/L and maintaining that concentration to that value (or lower by precipitation?) during 8 days. They found that it resulted in a loss of approx 65% of the zooxanthellae in Porites lutea from an unpolluted site.

From the paper:
"A semi-static bioassay was used to test the toxicity of iron in seawater to the corals. Five colonies from each site were placed in each of four fibreglass containers which contained 20 1. aerated seawater. Using a stock ferric nitrate/seawater mixture, the metal salt was added to three of the containers to give final concentrations of 0.005, 0.01, and 0.05 mg 1 -I Fe respectively. The fourth container was employed as a control. The experimental solutions were renewed every 12 h throughout the 8-day experiment. The animals were maintained on outdoor wet tables, which were well-
exposed to daylight. Although the corals were not fed throughout the experiment, small particulates were available to the animals from the seawater used in all experimental treatments."

Iron is, just like many other heavy metals, highly essential but can become toxic if it is present at high enough concentration and is bio-available.

From the Harland and Brown study it looks like iron is toxic towards zooxanthellae when present in a too high concentration.

From their paper if a material is capable in continuously releasing iron and the concentration is maintained at a high concentration loss of zooxanthellae could occur, leading to obvious SPS mortality.

<a href=showthread.php?s=&postid=5921401#post5921401 target=_blank>Originally posted</a> by solbby
Metal tolerance in the scleractinian coral Porites lutea. Harland, A. D.; Brown, B. E. Cent. Trop. Coastal Manage., Univ. Newcastle upon Tyne, Newcastle upon Tyne, UK. Mar. Pollut. Bull. (1989), 20(7), 353-7.

Abstract

Exposure of the scleractinian coral P. lutea to elevated iron concns. leads to a loss of zooxanthellae (symbiotic algae) from the coral tissues. This response is very marked in corals not regularly exposed to high environmental concns. of iron. For corals exposed to daily run-off from an enriched iron effluent, the response is diminished, suggesting that these animals may have developed a tolerance to the metal. In the field, corals from a polluted site exhibited significantly higher levels of iron in their tissues than did those from an unpolluted location.

 

[foshizzle]

ferricNITRATE?
I'm no chemist, but it seems like other componds would have been better since nitrate is known to have similar effects.

From Randy H-F:
"The concentration of iron varies substantially with location and depth, and is depleted at the surface due to scavenging by organisms. Typical surface concentrations are on the order of 0.1 nM (0.000006 ppm). When not bound to an organic molecule, iron in seawater exists primarily as dissolved Fe(OH)3. Iron(III) is quite insoluble in seawater at pH 8.2 due to the formation of iron oxides (rust) of various compositions. In fact, it is one of the least soluble cations in seawater. So dumping in a lot of unbound iron into a reef tank may simply result in much of it precipitating onto the bottom."

"Since the foods delivered to reef tanks contain a large amount of iron, how could the water column ever be ââ"šÂ¬Ã…"œlowââ"šÂ¬Ã‚ in iron? In the case of iron, there are several potentially important export mechanisms from reef tanks. Iron bound to organic molecules may be readily skimmed, depending on the nature of the organic. Iron is also taken up by the many organisms in the tank. Also, iron in the water column may simply not be bioavailable when chelated to certain organics (as mentioned above and discussed in more detail below). Finally, iron may precipitate in any of the varied environments present in a reef tank. These include high pH environments where certain additives are introduced (like limewater), potentially causing rapid formation of iron oxides and hydroxides. It is also possible that iron binds onto calcium carbonate surfaces, both those present as sand and rock, and those being created as coral skeletons and other biological structures. "

 

[foshizzle]

... and here's his other iron article discussing the study above. http://www.advancedaquarist.com/issues/oct2002/chem.htm