Supplements

[ChrisP]

In a 32 gallon reef with soft corals and with a monthly 30% water change, what would be the most efficient method of supplementing calcium and alkalinity? Do I need to supplement strontium, magnesium, iodine, and trace elements? If so, what would be the most efficient method of doing so?
Chris

 

[IslandCrow]

Depending on your calcium and alkalinity uptake, which I'd imagine is pretty minimal, I would first try using a kalkwasser dip. You can either buy the LFS stuff or save some money buy pickling lime (not pickling salt or spices) from the grocery store or Walmart. Mrs. Wage's is a popular brand. If that doesn't meet the demand, a two-part supplement (ESV and Kent both make good ones) is probably your next most cost-effective solution. I'd imagine you'd only need to dose once a week on a softie tank.

Soft corals use little if any calcium or alkalinity, and water changes alone are usually sufficient. Your coraline will love you, though. Some soft coral keepers swear by iodine, but I never touch the stuff. It's easy to overdose, and I've been told by chemists that there's no reliable method in this hobby to test for all the different forms this ion can take (iodide, iodate, iodine, etc.). Strontium I believe is useful mainly for hard corals, but again, I never touch the stuff. I am a firm believer in magnesium supplementation, but that's because it's believed to help in the uptake of calcium, so for my soft coral tank, I do not dose it. All other trace elements will be replaced with your water changes.

So, very short answer (bet you wish you'd skipped to the bottom). . .you can more than likely get by with water changes only and no supplements. But if you do supplement, be sure to test for anything you supplement.

 

[ChrisP]

Thanks, IslandCrow - very sound advice. Since I wrote my question, I've decided to add so low light hard corals - maybe an open brain, torch, hammer, etc., so CA will become an important issue. I built a simple DIY drip system and intend to drip about a gallon per day of kalkwasser. Does this sound adequate? Also, I Have a bout 160 watts of PC lighting in an 18" deep, corner-style aquarium. Do you think this will be sufficient for the types of hard corals I mentioned?
Thanks again!

 

[IslandCrow]

You can usually get away with adding as much kalkwasser as you will lose freshwater to evaporation. Keep a close eye on your PH, though. That's your limiting factor for kalkwasser addition, when your PH gets too high. Adding some white vinegar to the kalkwasser will reduce this effect. About 10-20 ml of vinegar per gallon is usually a good amount. If you start seeing algae growth in your tank, cut back on the vinegar. Some people will also dose their kalk only at night. Your PH is lowest then so it can more easily handle the rise caused by the kalk. It also keeps your overall PH levels more stable.

I think your lighting should be just fine. I kept those same corals under 96w of PC lighting for about 6 months, and they seemed to do fine. I'm really not a lighting expert, but those are definitely good choices for hard corals under PC lighting.