Just after some advice re: Magnesium. I tested my magnesium today using salifert kit for the first time and mag was 1170ppm, Kh = 7, Ca - 400ppm, salinity 1.025, phosphate - zero (reads as this but i know its probably higher).

anyway so i should probably look at raising the magnesium to around 1250ppm? So i'm not too familar about how to raise mag, but from what i've read i should look at getting some mag flake. How do you dose this in to the aquarium and where can i get smaller quantities of mag. I've read you can buy 25kg bags but this would probably take a long time to get through.

I use the Seachem stuff. Mine was sitting about the same as urs until I boosted it up. Directions were mix with freshwater. Its something that once you get up to the desired level, u shouldn't need to change it bar a massive water change or other undesired event.

How large are the seachem jars of magnesium and how much did you use to get your mag level up?

there are various sizes. Use the calculator to find out how much you need, it has seachem mag on it... You don't need to dose mag as often as Ca or Bicarb...

Have a look at this calculator:

http://reef.diesyst.com/chemcalc/chemcalc.html

(Its in the links to reference sites post)

This is what I use for dosing:

Epsom Salts for adjusting my magnesium, you can buy it from the chemist in 500Gram containers.

Seachem Reef Adv Calcium (Dry) for my Calcium

Baking Soda to adjust my Alkalinity.

I only adjust one at a time, and mix into my top-up water (I use a Jug-o-meter 1000ml) and adjust my NSW in my 60L barrels for water changes.

Since my tank doesn't have a big bioload (8 month old), I don't have to dose much in my top-up.

cheers guys, will take a look at the calculators

I'd aim for mg of 1350 1170 isnt that bad just not the desired level. Remember to split the recommended dose into two..... dose half the amount, test the next day and if needed dose the other half.

great cheers, had a look at the calculators and they're very helpful, need around 700gms to get it up to 1350, had a look and saw that the seachem products come in in 1, 2, 4 and 20kg ranges so will head off to the shops tomorrow .

I'm sure mine was a 500ml one which was enuf to bring the level up to 1250

doesnt mean much when we dont know your tank volume or your Ca/Kh balance

I know his tank is 350L not sure on the other stuff though

great cheers, had a look at the calculators and they're very helpful, need around 700gms to get it up to 1350, had a look and saw that the seachem products come in in 1, 2, 4 and 20kg ranges so will head off to the shops tomorrow .

20kg hmm where do you get that from i am right out, so is our LFS.

20kg hmm where do you get that from i am right out, so is our LFS.

Pop over and grab some bro.I got heaps.

20Kg lots was just on the seachem site, had a look at the lfs and they only sell the smaller volumes, obviously 20kg isn't in demand over here.

i think you can get a 500g for around 30 to 40 dollars or 20kg for 50 to $60ish,

yeah that seemed about the price at the lfs. Am thinking of either seeing if i can source some mag through some contacts or might look in to using epsom salts as camnbron, is there any risk to using this, is it likely to contain unwanted contaminants? Are there different grades of epsom salts available?

I have quite a bit left over in my garage, it is what i used on my own tank so you know it would be safe. Flick me a pm and you can come and grab some if you like.

thanks tm

The stuff from an lfs costs 50 bucks a kilo or something similar. If you are prepared to buy a 25 kilo sack you can buy magnesium chloride, of the same or better quality as the stuff at the lfs, for something like 4 bucks a kilo, from medchem, here is their website http://www.medchem.co.nz/

Or, if you want to go real cheapskate (like me), you can get magnesium chloride from a farm supply shop for something like 13 bucks for a 25 kilo sack. However the quality is not assured, it is used as a feed supplement to milking cows to help replace the magnesium they lose in the milk. However I have been using this cheap stuff for several years.

Epsom salts is also OK but using a large amount of it will cause an ionic imbalance, with too many sulphate ions. Epsom salt is Magnesium sulphate. In NSW, chloride ions outnumber sulphate ions about 10 to 1. So if you want to make your own magnesium supplement with a correct ionic balance, you mix 1 part epsom salt, to 10 parts magnesium chloride. This is most likely what the Seachem product is.

However having a slightly incorrect ionic imbalance in the tank is not a major although can have some effect.

Thanks for explaning it wasp. I had initially thought about epsom salts after camnbron's suggestion but read that if you are increasing by more than 100ppm of magnesium that the sulphate increase may be too high. Luckily I have been offered some magnesium so that will sort me out