Seachem's response to Excel question


Prolific Poster
Oct 17, 2007
South Florida
I asked Seachem about Excel killing or adversely affecting my fish, their response:

Flourish Excel is a reducing agent and has the capability
to remove some oxygen from the water. If you already have
a low oxygen content in the tank and dose Excel, this
could potentially have an impact on very sensitive fish.
However, this is a rare situation. We have these types of
fish in our tanks here and we dose Flourish Excel on a
daily basis with no problem. If you are using another
reducing agent along with the Flourish Excel, it is
possible that the fish are becoming stressed due to lack
of oxygen. Most water conditioners are reducing agents.
You may just need to add the Excel on days when you do not
add any other supplements and add less than the
recommended dose. As I said, this is not a typical
reaction with Flourish Excel. It is most likely not the
Flourish Excel alone, but a combination of factors.
Tech Support
Tech Support
Seachem Laboratories, Inc.
1000 Seachem Drive, Madison, GA 30650
888-SEACHEM Fax 706-343-6070

Tom, what other "reducing" agents may be in my EI fertilizing doses.
Are Epson Salt, Baking Soda, NPK reducing agents?

tks, raul

Tom Barr

Staff member
Jan 23, 2005
Nope, NPK etc..... they are "salts".

Reducing agents are compounds that donates electrons.
If something is reduced, it gains an electron.
If something is oxidized, it loses an electron.
What is the difference between Chlorine and chloride?
One is toxic as all get out, while the other is not, ask yourself "why?".
Since NaCl and KCl are "salts", and when added to water, are not reducing agents or Oxidizers, what do you think?

Salts are formed by a chemical reaction between:
A base and an acid, e.g. NH3 + HCl -> NH4Cl.
A metal and an acid, e.g. Mg + H2SO4 -> MgSO4 + H2.
A base and an acid anhydride, e.g. 2 NaOH + Cl2O -> 2 NaClO + H2O
An acid and an basic anhydride, e.g. 2 HNO3 + Na2O -> 2 NaNO3 + H2O

Salts can also form if solutions of different salts are mixed, their ions recombine, and the new salt is insoluble and precipitates.

The Cl in NaCl obviously is not Chlorine correct?
Otherwise salt water would kill everything in it.
Why is that?
I'll let you ponder and look.

Reducing agent - Wikipedia, the free encyclopedia

Give it a read.

Redox - Wikipedia, the free encyclopedia

Tom Barr