PDA

View Full Version : Farley dosing and trace elements


epsaxon
12/19/2011, 12:00 PM
I am in Vietnam and trying to establish a 600l total water volume mixed reef. Getting reputable brand name additives on a consistent basis is near impossible. Luckily, I can get all the 95% to 100% pure chemicals required for the Farley recipe 1 for next to nothing in 5kg bags. The Farley recipe uses CaCl2, Na2CO3, MgCl2 and MgSO4 but before I start dosing:

- Can I substitute CaCl2 and MgSO4 with CaSO4 and still obtain sufficient Mg and SO4 levels? What would be the mix ratio if this is possible?
- What about other trace elements such as iron, strontium, iodine, etc.? I do not know why but Fiji Gold is readily available here and I know Fiji Gold is Ca2CO3 based but it does claim to have trace elements. Are they in a form that really is usable by the corals? Aside from commericaly prepared additives, what bulk chemicals could I use for trace element supplementation?
- Is Kalkwasser pure Ca(OH)2?

I know this is a lot to ask but any guidance will be appreciated as local knowledge is limited as they seem to be more interested in selling more corals than allowing them to live. I have yet find a saltwater test kit in country!

Randy Holmes-Farley
12/19/2011, 02:55 PM
Can I substitute CaCl2 and MgSO4 with CaSO4 and still obtain sufficient Mg and SO4 levels? What would be the mix ratio if this is possible?


You mean no magnesium part? The magnesium is needed to keep magnesium from being depleted.

Is Kalkwasser pure Ca(OH)2?


It is Ca(OH)2 or CaO dissolved in fresh water, yes.

What about other trace elements such as iron, strontium, iodine, etc.?

In general, I'd suggest getting most trace elements added or removed when in excess via water changes. Do you have access to a decent salt mix?

Iron is one you might consider if you grow macroalgae.

epsaxon
12/19/2011, 11:18 PM
Thank you for replying

You mean no magnesium part? The magnesium is needed to keep magnesium from being depleted.

I was thinking I could modify/simplify your recipe to use CaSO4, MgCl and NaHCO3. It would be to reduce cost even further but I do not know if it will work or how to determine the proper mix ratio.

It is Ca(OH)2 or CaO dissolved in fresh water, yes.

Great, so now I can dose following the same method and precautions as Kalkwasser.

In general, I'd suggest getting most trace elements added or removed when in excess via water changes. Do you have access to a decent salt mix?

Iron is one you might consider if you grow macroalgae.

I was hoping that would be the case. I grab salt mix whenever I can find a brand that I think is good but it is hit and miss so I cannot always get the same mix. Currently using Instant Ocean Reef Crystals but I have one bucket each of Brightwell Neomarine Reef and Red Sea Coral Pro. If need be I could import it just as I did for the Salifert test kits.

So, in your opinion, is the Fiji Gold completely useless even as a trace element (non calcium) additive? I have been dosing it at about half the recommended dose and I have not seen anything really positive or negative as a result. I do a 25% water change monthly so I figured the Fiji Gold was just holding everything steady between changes.

bertoni
12/19/2011, 11:57 PM
I think the Fiji Gold is worthless, personally. It's effectively just fine sand.

I don't think you can use calcium sulfate in place of calcium chloride without causing skewing the ionic balance a fair amount. Plenty of water changes could fix that, though.

bertoni
12/19/2011, 11:57 PM
I think the Fiji Gold is worthless, personally. It's effectively just fine sand.

I don't think you can use calcium sulfate in place of calcium chloride without causing skewing the ionic balance a fair amount. Plenty of water changes could fix that, though.