Need more help with my columbian sharks please

[daviem]

Hi all,

.........I had been told by 2 3 manufacturers the GH of the marine salt is already quiet high even at low salinity but I had to check myself and it turned out they are correct (of course what Im saying is based purely on Columbian sharks) the GH would probably be too low with RO water for a Marine fish at 1.006 but then so would the salt content, there does seem to be an issue though the KH isn't great at this salinity.....

Have a look at the composition of sea water, Lenntech is a Dutch company, so they use a "." as the thousand delineater.

Parts per million (ppm) and mg/L are equivalents, so the levels of chloride (Cl-), sodium (Na+), sulphate (SO4--) and magnesium (Mg++) all in the thousands of ppm (Mg = 1260 ppm, 1.26 ppt etc) and calcium (Ca++) is 400 ppm. Together the Mg++ and Ca++ ions are the dGH, and bicarbonate (HCO3-) 140 ppm is the dKH.

The reason the level of HCO3- is lower is to do with the low solubility of carbonates, there is an enormous buffer of biogenic CaCO3, which always maintains that level and also means the pH is "stable" at ~pH 8.

cheers Darrel

Thank you

[Fishmandavew]

Chlorine and fluorine in our uk water is not your problem, both can be overcome by a decent dechlorinator. Although, I live in Yorkshire and have never used the stuff. All my water changes come straight from the tap for my freshwater stock and have for 40 yrs. flouramine amd chloramine are our new issues and your dechlorinator won’t remove those.
That said I run RO for my marine and would suggest that if you are mixing brackish conditions for your Columbian sharks then personally I would mix RO water with hot tap (assuming no lead pipes etc) and mix with a good quality marine salt to get the desired salinity.
RO is ideal for mixing salt or brackish water when used with quality marine grade salt, replenishing lost minerals, etc.
What size are your shark? I moved mine to brackish at 5-6” and they were in full marine by 9-12”.

[Viktor Jarikov]

Great input from one of our most seasoned veterans.

Chlorine and fluorine in our uk water ... flouramine and chloramine are our new issues and your dechlorinator won’t remove those.

May or may not be off topic but this is the first time I hear of fluorine and fluoramine as a treatment used for city water as well as the first time I hear that dechlorinators do not remove chloramine as I have always thought and read that they do, at least Seachem claims that.

[daviem]

Chlorine and fluorine in our uk water is not your problem, both can be overcome by a decent dechlorinator. Although, I live in Yorkshire and have never used the stuff. All my water changes come straight from the tap for my freshwater stock and have for 40 yrs. flouramine amd chloramine are our new issues and your dechlorinator won’t remove those.
That said I run RO for my marine and would suggest that if you are mixing brackish conditions for your Columbian sharks then personally I would mix RO water with hot tap (assuming no lead pipes etc) and mix with a good quality marine salt to get the desired salinity.
RO is ideal for mixing salt or brackish water when used with quality marine grade salt, replenishing lost minerals, etc.
What size are your shark? I moved mine to brackish at 5-6” and they were in full marine by 9-12”.

Thanks, They’re 3 and a half inches and I’m having a nightmare with heaters playing up, the external filter I added to help the cycling overheating and getting the tank cycled just isn’t working I asked Seachem if their bacteria live in brackish water all they say is in freshwater and marine nothing about the inbetween aka brackish, does the RO system remove the stuff the decolorisation doesn’t?