Is magnesium dosing a Must?

[Mark 75g]

I have a 175g mixed reef but mainly sps. I do about 30gallon water changes every week. I use reef crystals
I dose 2 part akl and calc. everyday.
All my corals are growing and have good color.

Wondering if dosing magnesium would help with color and growth or is it not worth it because the magnesium dosing seems to be very expensive with using Bulk reef supply product.

 

[MHG]

It depends on what you measure it at. I do a 20% once a month and add some salt mixed water to maintain my salinity weekly (from the loss of salt water from the skimmer, testing and drip acclimating) and my magnesium is over 1400 consistently.

 

[USC-fan]

Yes you need it. If you are not using a test kit i would buy one.

You can buy 5 gallon of mag supplement for $28 and about $20 shipping. Just a heads up the shipping they charge at checkout is only about half the true shipping cost. They will send you an invoice for the rest.

http://www.buckeyefieldsupply.com/showproducts.asp?Category=240&Sub=124

that should last you many years and about $10-$20 cheaper than bulk reef supply and its the same product.

 

[legky]

For my opinion. Your tank should change water 10% of average water in tank that 17-18 G that enough. If you change water much to make Ca Kh swing. For Mg i do not worries about it. Just keep Mg 1230-1300 that fine.

 

[MammothReefer]

Yes magnesium is a must. Magnesium directly relates to your ability to maintain consistent levels of alk and calcium. How ever magnesium is one of those odd things where it won't budge for weeks/months then all of a sudden it will just plummet. For months on end I had stable mag. I was only adding it sparsely, then something changed and now my tanks mag is in constant flux, so much so that I'm now going to be using a 3rd doser for mag. As far as cost if you aren't needing much because of high mag content in your salt then the cost is negated as you won't be using very much. I use BRS for all 3 supplements and I'm still on the first batch for almost a year and a half now.

However like others said you have to test.

For me mag is currently the second most frequent thing I test after alkalinity.
Here is a link to my log file, it might help so you can see how things tend to "move" around when only dosing 2 part and not 3 part.

https://docs.google.com/spreadsheet/ccc?key=0AiJkwwBTLCi7dG12ZFhsTXBGTUFZellSWTZ3QkhiLVE