crud in salt H2O mixing reservoir

[rsaund]

Hi,

I have a 35 gallon plastic reservoir in which I mix and hold salt H2O ready to use for water changes. I have used a variety of salt mixes. Over time, the reservoir has developed a brownish crust that I assume is due to some minerals from the salt mix. The crust partially flakes off into the water when I vigorously mix the water, and eventually settle to the bottom, but doesn't totally dissolve. It's gotten really gross, so I'm cleaning it thoroughly. My questions are:

1. do those of you who have reservoirs like this experience crusty brown stuff over time?

2. do you think it's harmful (i.e., should I bother keeping up on the cleaning more than once every couple of years?)

3. I'm using vinegar to clean it. Assuming I rinse very thoroughly, any problems with this?

THANKS

Robin

[otolith]

Another reason to NOT do frequent water changes...haha I would think the crud, at least if it's brittle, is probably precipitated minerals that just built up over time...The vinegar should be fine, just rinse thoroughly afterwards.
Derek

[Graham]

Precipitated minerals and insoluble "impurities". The chemicals used to make salt mix is not really very high quality stuff (that's why alot of the trace minerals are at such ludicrously high levels). Since they are precipitated and/or insoluble, it wouldn't really matter if a bit made it into your system - they don't react with water (insuluble impurities anyway). Vinegar is your friend - I always have a gallon on hand.

BTW, someday oto will learn the way...change your water, boy!

[otolith]

Originally posted by Graham
BTW, someday oto will learn the way...change your water, boy!

Actually, I've been trying to change 5g every week, but have had a few corals bleach (and die!!!) since I started, but I can't associate the water changes with the corals bleaching...

[Graham]

You aren't using Crystal Sea are you?

No, I know you aren't...

I have a guess:
It's possible they aren't used to all that spankin' new water.
If there are metabolites, nutrients, metals and/or such accumulated in the water, it's possible that the corals had been putting more into photosynthesis. When the levels of these things decrease, photosynthesis is less inhibited/compromised and they "overphotosynthesize", then bleach before they can adjust. Just a guess - I have read some things along these lines (not directly with water changes, but rather ralating to "not clean" water. No offense, eh .)

Did it happen after the first change, or did it take a few changes to see that effect?

[capman]

White vinegar is totally harmless, aside from the fact that if you put *a lot* of it in your tank it is going to affect your pH. Some of us (me anyway) even add vinegar to our limewater in our reservoirs to enhance its effectiveness.

I don't now how much chemistry you know (and I'm certainly no chemistry expert myself), but vinegar is just dilute acetic acid. Acetic acid dissociates (separates) in water into hydrogen ions and acetate ions. The hydrogen ions are what cause the pH drop mentioned above (pH is a measure of hydrogen ion concentration...the negative log of hydrogen ion concentration in fact). Acetate ions are basically just really short carbon chains, which happen to be useable as an energy source by various bacteria in your system. The bacteria break down these acetate ions, producing carbon dioxide (and I'm assuing also water) as a waste product.

[capman]

[capman]

By the way, if you want to see the rationale for using vinegar in limewater go to: http://www.animalnetwork.com/fish2/a...io/default.asp

[happy]

I have the same thing in my salt reservoir. it is not a problem, and I clean it out about every 3 years.