brown/gray "sludge" (precip) when mixing new saltwater

[Gary Majchrzak]

who else reading this has experienced it?

my saltmix turnover rate is probably much quicker than most so I'm using recently manufactured saltmix. The precip forms on the bottom and sides of the mixing vessel and also on any pumps used for mixing.

it happens with many brands of saltmix.

it doesn't appear to be harmful and (in at least one case) a salt manufacturer has actually stated that it's beneficial to the final outcome of the product:

read this
Brown deposit in H2Ocean Pro Plus Salt
Question:
I have recently bought a new tub of the ocean salt.
When mixed it is leaving a brown residuue on the bottom of the buckets.
I belong to a marine club and no of many other members who are experiancing the same problem.
Can you comfirm if the salt is contaminated of this is a harmfull substance.



Answer:
This brown residue is detailed on the instructions in the tub and is a residue of ferric oxide/hydroxide from the manufacturing process, (like Rowaphos). This product will bind to any phosphates and heavy metals in the water and allow them to precipitate out for removal via the skimmer.

The presence of the ferric deposits depends on the calcium source that we use to boost the calcium level. The best calcium source to use for incorporation and solubility into the final salt solution is the one which contains this ferric residue however as people tend not to like the brown deposits we do not generally use it. We have however had one batch in the UK, of which you must have received a drum, which did have such a residue as there was a supply issue on the normal calcium chemical.

This deposit is not harmful in any way and is actually beneficial to the final mix.

I hope this answers your query


related thread

and there's more to be found with a search....

 

[Gary Majchrzak]

fwiw

fwiw

ALWAYS check new saltwater before using.

"Bad batches" can be found in almost every brand- from the most expensive to the cheapest.

Tropic Marin is a relatively very expensive saltmix

 

[wah-zoh]

I got that sludge and I use reef crystals. I also had high tds readings on my r/o water. So that explains it it. I have been buying buckets of r/o from lfs and I have not had the sludge since. Cool find

 

[Gary Majchrzak]

I got that sludge and I use reef crystals. I also had high tds readings on my r/o water. So that explains it it. I have been buying buckets of r/o from lfs and I have not had the sludge since. Cool find

fwiw IO and RC are practically the same with a few minor differences.

If the sludge is actually "residue of ferric oxide/hydroxide from the manufacturing process, (like Rowaphos)" than it would certainly make sense that tapwater (ie:high TDS) could possibly cause more precip to form.

 

[Greg 45]

FWIW I had similar problem with two pails of Brightwell salt.
I made a post about salt brands being to pure .
I now use ESV never mixes up dirty.
Also Gettanked salt mikxer clear.

 

[Gravesj1s]

For the past 2 years Ive used instant ocean & reef crystals.Both have mixed and produced the brown precipitate.

The manufactures response was pretty interesting and differs somewhat from the responses I got when asking about it.A few of the chem wiz guys were implying it was common,normal,safe and likely Mg I was seeing.
I did notice with any reading at all from TDS output I would get a brown slimish algae (looked alot like a diatom) in my saltwater mixing bucket,even though it was kept covered,no light exposure.
Seemed odd and have noticed other posters mention it ,but ive only noticed it appear with TDS 1-2.Other than that ,I still get the precipitation but but have'nt noticed anything negative in my tank from it.As long as TDS from ro/di is a firm 0.

 

[Kent E]

I don't know if this is the case here, but it wasn't that long ago there was some sources of mined calcium that had "tainted vanes" that were naturally occurring in the mine. This created brown gook in the bottom of the mixing container. Again, I'm not sure if this is what's happening here.

 

[block head]

i get the brown sludge w/RC. i did a complete rebuild of my rodi unit (membrane /filters) . i usually make 5g at a time. i make sure to mix the bucket well, and add salt slowly to rodi. it's more annoying, than harmful IMO. if i could get another brand for $40 a bucket, i'd think hard about switching.

 

[block head]

I don't know if this is the case here, but it wasn't that long ago there was some sources of mined calcium that had "tainted vanes" that were naturally occurring in the mine. This created brown gook in the bottom of the mixing container. Again, I'm not sure if this is what's happening here.

my bucket usually lasts a year. i bought mine almost a year ago.

 

[Capt_Cully]

I used to get all bent out of shape about the build up in the mixing vat, but have long believed it to be harmless. I give the mixing vat a solid scrub every month or so (4-5 water changes), and go on living my life.

I'd second what Gary said. I used to check EVERY new bucket. I only started this after getting burned in the whole "Bad Batch" of Reef Crystals, which supposedly never happened, but everyone seems to have experienced.

As a reef matures, paranoia increases, perhaps exponentially. Checking new bucket's numbers, will help keep this in check a bit.