Dosing for Mag, DKH

Hello all have a few questions on what and how everyone is dosing for Mag and DKH. My current water chemistry is as follows.

Salinity- 1.026
Temp- 79
PH (Mid day lights on)- 8.3ish running api.
Mag- 1280
DKH- 6
Cal- 440

Typically my tank is very stable, but recently I have seen a few larger swings. Which is why I would like to start dosing as needed for Mag. I have been dosing 2 part sechem for a while now as needed (not much until now, I've added alot of coral lately).

What would you guys suggest to dose for Mag? I would really like to stay away from anything without a label ie household salts.

Also, I would like to get my DKH up to the 8-9 range (I run a bio-pellet reactor and have heard its best to keep it a little on the low end). If I just dose additional alk of the 2 part this will lower my Cal. also correct? What would you suggest for this.

I really like BRS, but I really don't like the thought of mixing my own 2 part solution +I work a ton so quick and easy=win. Also, kalk mixes sound like a PITA so would like to stay away from this as well.

 

You can buy liquid Mag supplements from Seachem, Kent and others. Your Mg is at natural seawater level right now so it is good. You can raise Mg 100ppm per day.

Dosing more alk will lower your Ca a little but not much. Try to dose your Ca and alk an hour apart to keep them from precipitating out as easily.

 

Thank you 2in10. After reading a little more about suggested levels I may hold on out dosing Mag for now. I've just recently started the switch to reef crystals salt, so well see how things pan out this way. I would like to up the amount of Seachem Reef fusion part 2 to increase my DKH. I've only been dosing ~12ml of both as needed (weekly or so, WC's have kept up mostly on Calc.). Any suggestions on how much of each I should dose to keep Calc. at 420+ and to move DKH to the 8-9 range?

 

I read an interesting article recently about alk and ca and growth of corals. I would only be concerned in getting your alk up a little but as your mag and ca are both fine.

The article referenced some studies about CA levels and coral growth and basically a Ca of under 360 inhibited growth but levels above 360 had no correlation to growth wheather your CA be 360, 400, 450, etc you get the idea. I guess the coral takes in CA and makes a supersaturated calcium mix right under the flesh and above the skeleton and it was theorized that if your CA drops under 360 than the coral will have a difficult time maintaining the supersaturated CA solution within itself due to CA leaking into the surrounding water, but above 360 the coral only took in so much calcium that it did not relate to overall CA levels in the water. The only benefit of keepng it higher in a small tank vs the ocea is the fact that CA can become depleted quickly and if your at say 360 or 370 it may drop low between WC, but if you at 440 I would hold off on dosing unless you see quick drops in CA between your WC.

As far as alk the study did suggest a directy correlation with alk levels and coral growth. To low and the corals struggled obviously, but as the alk rose higher than natural levels the corals growth accelerated. I do not recall if it maxed out at a high level or not but an alk of 6 is a little low so dosing alk would directly benefit your corals.

Only thing I know about Mag is it will help keep your CA and alk stable from precipitating out. They suggest your level be 3X your CA which you are only 40 pts off so unless you see a lot of sudden drops I would leave your Mag as be.

As for what to dose with I think like everythign else those all in ones are for the ones who have yet to discover the benefits of dosing specifically what you want. I am a fan of the aquavitro line where eight.four doses alk calcification doses CA and there is another for Mag that I do not know. My Mag is always 1400-1500 so I never bought anythig to dose mag. They also have a product called balance which I use that is supposed to help create the proper balance of bicarb and carb. Redsea makes an A B and C product that is basically the same thing, alk mag and ca, and there are many others. Gives you much better control than an all in one bottle that you dont really know what its goign to raise

 

Just keep adding 1ml until you find an amount that keeps you in the range you want. I would do an extra dose of part 2 and see where it bumps your alk to. Repeat daily until you reach the range you want.

 

Thanks for the post pgh, very informative. I'll have to look into the alk studies to find the right level for my system. I have heard of issues with corals getting alk burn in systems with high alk and bio-pellet reactors, so I'll likely try to keep it a tad lower then others.

 

So, I dosed 15ml Part 1 and 30ml part 2 last night. Calc. has stayed at 440 and DKH has moved to 7. Is moving DKH up 1 point per 24 hours ok? It would be nice to be in range within a few days.

As a side note I have noticed that my hammer coral looks ALOT better this morning.

 

After some more research it looks like the recomended DKH level is around 8 for this type of system. I think I'm going to give one more dose, like I did last night, tonight and hope to stay in the 8DKH range.