alkalinity

[Jmck]

Ok, so my alkalinity is low, but my red sea supplement kit says for growing sps frags you should get your dkh all the way to 12.4?!! this seems really high to me?

Most people here keep it around 9dkh I believe

 

[parrotchute]

6-7 is fine.

 

[Jmck]

Really? for SPS?

I can see for fish it would be fine but alk is very important in skeleton growth? But how high is too high

 

[parrotchute]

To get that much alk balanced with calcium, I think you'd need a pretty low pH.

 

[parrotchute]

6-7 is natural dkh for the ocean. The problem is that as you try to raise alk, your calcium should be balanced with it so it doesn't fall out of solution. As pH raises, the level at which it is soluble decreases.

 

[Jmck]

I dont understand.

Alright, so I have a calcium level at 450ppm an da dkh of 5.

If I rais my alkalinity to 8 my calcium will not stay at its present value of 450? disregarding use of tank inhabitants. And my PH will decrease as well as alk increases?

 

[parrotchute]

What's your pH right now? If it's low, use sodium carbonate, if it's high use sodium bicarbonate and raise your alk to about 8. THen you should be balanced.

 

[parrotchute]

The higher the pH, the bigger the chance it will precipitate and fall out when you increase alkalinity.

 

[Jmck]

well my PH is 8-8.2

So that seems within the perfect range. with my alk at 5 im going to bring MG up first from 1000, to 1350 then bring alkalinity up as well. I dont know how fast I can bring my Mg up though.

 

[parrotchute]

That sounds perfect. I wouldn't stress on the alk too much yet - you're maintaining good calcium and the alk isn't at a critical level. Once the mag is stabilized, add some alk supplements. If both alk and calcium go too high, just let the corals consume them until they drop into normal levels, then dose as needed to maintain.

Once you get mag to the right level, it's not too hard to maintain as it is used a lot less than the CA.

I'd highly recommend Bulkreefsupply's mag/ca/alk bulk supplements and their instructions. They make it easy and way cheaper than dosing the pre-made liquid supplements.

 

[Jmck]

Thanks parrotchute, I have just started to use the new red sea stuff, going to try their 'complete reef program' as it looks really well designed and thought out.

So can I bring my magnesium up by more than 100ppm a day?

I still dont understand why the alk buffer packaging says to maintain 12.4 dkh to grow sps corals, but to maintain a mature tank it says to keep it at 9dkh

 

[parrotchute]

Yeah,. I personally think 12.4 would be pretty high, with 6-9 being a decent range. My personal opinion, but I think stability is more importantly. Basically, as long as it is stable in that range, there is enough "free" calc/sod bicarbonate to be used by the growing corals.

6-7 is lower, but it's what seawater is at, and corals grow fine there! But having more in abundance will help. I think 12 is pretty high tho and would be expensive/difficult to maintain.

I'd only raise mag 100ppm a day, maybe 200ppm MAX. I've heard it can shock the inverts.

 

[Jmck]

ok fair enough, thanks again for all your help and useful information :)

I guess 12.4 could be ideal for the abundance of nutrients, but probably really hard to maintain.

Interesting though, it says the higher you go, the less you need to keep it at that level. These kits are made for daily supplementing so ill see what i can keep a stable water condition at. This is going to be a fun little test. Need to start writing results in a book now as well.

 

[parrotchute]

You bet, I'm no expert on alk/calc - I always get confused, but it IS a confusing topic!

Yes, once you get it to the level you want to maintain, all you need to do is add supplements to match the demand. I think it will be pretty expensive in the long run, compared to bulk mix-it-yourself 2-part.

Here's what wet web media had to say on alk/ca - they suggest an alk range closer to what red sea recommended:

"Ironically, within the recommended ranges of 350 and 450 ppm Ca (calcium) and 8-12 dKH Alk (alkalinity) it is not necessary to maintain both parameters at the higher end concurrently. In fact, it is not practical or easily attained in most systems. In gross terms, high calcium and high alkalinity are mutually exclusive. Alas, too many aquarists get caught up in the roller coaster application of excessive amounts of supplements (randomly applied or not) and skew the balance of Ca and Alk in the system...Within the accepted ranges (350-450 ppm Ca and 8-12 dKH Alk), one parameter can be pushed to a high end while the other is allowed to stray toward the middle or lower end. Any reasonably mix of the two will still provide more than enough of both elements for successful calcification...Many aquarists enjoy phenomenal growth in their reef creatures with rather modest Ca and Alk levels. Indeed, consistency with all aspects of aquatic husbandry is more conducive to success than random high points. "

 

[Jmck]

ok, so basically, if you can maintain 450 ca and 9dkh, you should get a really good growth out of the tank, but if you can maintain higher, that is also better. But its about regularity, good to know. The plan now is to figure out what my daily dosing is and get that going. I want to have a perfectly stable system :) its easy to do if you wake up in the morning and make it part of your 'getting ready for work' routine :D

thanks gain

 

[parrotchute]

Yea, basically get it to the level you want, then test after a day. The amount depleted is the amount you need to dose daily. Once it's stable, you only have to test once a week or so to see if demand grew.

 

[Jmck]

welll parrot, I made a mistake testing, .2 ml of testing off actually, which is a lot when you look at the red sea titration tests.

After learning how to do it right. My alk is above 14 dkh (i buffered that slightly) my mag has moved up to 1400 (buffered a bit today, but doesnt help that the .2 ml off is a lot) and calcium is at about 550.

So now, I am going to wait for it to drop, to about 450 cal, 10dkh and 1300 Mg and then wait 4 days, work out how much went, divide it by 4 then start dosing daily :) and like you said, test weekly from there. Then, when my tank cleans up, start adding some more sps, and redo the test

 

[ccCapt]

I keep my alk around 8 dKH, calcium around 400 and mag around 1325. I would suggest not pushing alk up to the 12 range. Lots of corals don't like alk that high and can start to bleach. If your running your system with a low nutrient level, it's best to keep the alk around 8-9 dKH.

 

[Jmck]

Capt! the one man who would know the best for acro's ;)

Alright, ill keep it at that level. Btw, wanted to ask, how much cal, alk and mag do you use in a week with all the sps you have in your tank?

 

[ccCapt]

I DIY my supplements using baking soda (baked), calcium chloride (Dow Flake Ice Melt), mag chloride (DeadSeaWorks Mag Flake Ice Melt) and mag sulfate (Espom salts). I follow recipe 1 listed here: An Improved Do-it-Yourself Two-Part Calcium and Alkalinity Supplement System by Randy Holmes-Farley - Reefkeeping.com

I make up the supplements in 1 gal jugs. I dose aprox 120ml each of calcium and alk every day. When the gal jugs are about 1/2 empty, I dose about 1 cup of mag. Not to scientific. ;)