Aqaurium Water ?

Question
Hi i have an 120 gallon tank i'm trying to set up to saltwater. My tap water had a off the charts Aklanity level of over 16 dKH or 5.71 meq/l. So i Purchased an Reverse OS Filter sytemn whick lowered the level to under 2 dKH. I filled my tank and tested it repeatly and it was around 9-9.5 dKH so i started adding the Salt and now after adding about 2/3 of the needed salt my dKH test read 12.5. My question is Why am i having trouble keeping it down, Or is the Instant Ocean Salt raising My KH level?

Answer
Hi Mike,

This is a good question, and one which could have more than one answer. Regarding the Instant Ocean Synthetic Sea Salt, there is a great possibility that it could be playing a role in raising your KH Level.

My recommendation is to add magnesium. In natural saltwater, Magnesium is in the range of 1200 - 1300 ppm. It is important to maintain a level similar to this range because magnesium helps maintain levels of alkalinity and calcium. In conclusion magnesium helps to maintain levels with minimal impact to the ionic ratios found in natural sea water.

See the link below, it lists a good Magnesium that's readily available in the aquarium market. If you do decide to add magnesium, do it slowly, in minute amounts, and follow all of the manufacturers instructions precisely.

http://www.ocreef.com/seachem_reef_advantage_magnesium_600_g?category_id=0&searc...

My last piece of advice is to give your aquarium water some time to age itself; eventually it will start to balance out resulting in more consistent readings.

I wish you success with your new 120 gallon system.

Regards,
David