Having trouble raising my alk!

tomek77pl

tomek77pl

Member
Hi guys,


I have a 75 gallon with a 20 gallon sump and for the past two months I have been trying to get my alk up to about 9dkh. I use kent marine salt mix
:Specific Gravity: 1.024 - 1.026
pH: 8.2 to 8.3
Calcium: 550 to 575 ppm
Magnesium: 1,350 to 1,450 ppm


For the past couple or months my calcium stays about 425-450, mag stays above 1300 but my alk is 7dkh. After dosing the soda ash from brs( about 35ml a day) and with 2 20 gallon water changes I managed to get it to 7.6dkh. Am I doing something wrong? Should I do a 60 gallon WC? over three days and see where that goes or increase my alk dosing? I have a good amount of corals in my tank about 13 sps colonies but most are less then 4 inches. What do you guys think?
 
I have never been an advocate of "number chasing"....to me a stable number is more desirable than a specific number (although I am not saying a stable reading of 2dkh is good either ;))
while most people chase to get to 9,10 or higher dkh readings, I have heard and seen some very healthy and stable reefs running at 7 or 8dkh

on another note however, I do think your Ca level of 550-575 is a bit high and may or may not be affecting your dkh levels....

thats all I got....hopefully someone more knowledgable than I can chime in.... ;)
 
cet98 said:
I have never been an advocate of "number chasing"....to me a stable number is more desirable than a specific number (although I am not saying a stable reading of 2dkh is good either ;))
while most people chase to get to 9,10 or higher dkh readings, I have heard and seen some very healthy and stable reefs running at 7 or 8dkh

on another note however, I do think your Ca level of 550-575 is a bit high and may or may not be affecting your dkh levels....

thats all I got....hopefully someone more knowledgable than I can chime in.... ;)
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thank you for the response.The 550-575 is the calcium levels of the salt as it says on the box.
my current test reading of my tank as of yesterday is
1.025
Ca-425
mag-1320
Alk-7
 
oh....my bad.....then based on my original comment, I would just sit tight as is

this there a reason you're attempting to get to 9dkh?
 
Everyone That I speak to recommends the dkh for sps to be higher around 9, with having a good amount of sps in the tank, I have been trying to raise it.


cet98 said:
oh....my bad.....then based on my original comment, I would just sit tight as is

this there a reason you're attempting to get to 9dkh?
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Tom, some said over R2R and RC "the higher MAG then the ALK will lower". If you want ALK higher then less dosing MAG (If you do) and also dosing Baking Soda to raise the ALK. Search for Randy 2 parts dosing.
 
Chasing alk will only lead to problems IMO. Alk is the one parameter where drastic swings will cause nothing but bad to happen. Natural sea water is 7-8 dkh. Many people like high alk, but I've never read anywhere that higher does anything better for corals.

Stability is the key. I would rather have my alk at 7, than have it at 9 one day, the next at 8, the next at 9.5.

The most common parameters I've seen in really nice reef tanks are as follows:

PH-8.2-8.4
Cal-420-450
Alk-7-9
mag-1200-1500

For roughly 5 months I kept trying to keep my alk levels higher, but found that my sps weren't really growing at all. I've since stopped messing with the tank. The only thing I do now is use kalk in my topoff water and do water changes ever other week or so. I've noticed that sps frags I buy encrust within a week, where in the past, they would take over a month to encrust.
 
Yeah. You shouldn't worry about getting a high alk. Natural seawater has an alkalinity of ~7.5, that is the natural equilibrium. The only reason for bumping alk in a tank is to counteract the depressed pH that is found in a closed system. So check your pH if you want to chase a number, but an alk of 7ish will grow SPS just fine.
 
Thank you guys for the responds. My ph Has always been low, I can never get it past 8.05 according to my ph probe my ph varies from 7.87-8.03 in a day. I have a airline that suckus in air from the outside that leads directly into my skimmer and that bumps it a .02 or so. Could this be a problem? I haven't noticed alot of growth of sps in my tank so im tying to solve that problem. Another thing is would it be better if I switch my salts? kent marie mix? Since its very high in mag and calcium?
 
Have you tried, or thought about using kalkwasser in your top off water?

I had the same problem with lower PH levels, but ever since I started with kalk, my ph has been really good, even at night.
 
dont go to 9. maybe 8 or 7.5. magnesium is good. i think its your water change, if you dose then do a WC the alk will drop to balance with what your salt's alk is. Quit doing so many WC unless you have high nitrates or phosphates. thats why you change water, if you don't have high nutrients then just dose 2 part in equal portions. MG 1350 is a long way from 1450. to get it up to 1450 you need like a 600ml of mag supplement. 1350 is fine though. also if you go t some sps that will also eat up the extra alk you are adding, or maybe its your tank kinda buffering itself. blah blah blah.
 
DD said:
Have you tried, or thought about using kalkwasser in your top off water?

I had the same problem with lower PH levels, but ever since I started with kalk, my ph has been really good, even at night.
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Wouldn't kalk raise my calcium levels through the roof since it adds calc and alk?
 
tomek77pl said:
Wouldn't kalk raise my calcium levels through the roof since it adds calc and alk?
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It all depends on how much you use. You can do 1/8th of a teaspoon if that's really all you need. You can do up to 2 tsps per gallon since that's the maximum amount that can be saturated in FW. You can go higher by mixing in vinegar, but at that point you may as well get a calcium reactor.

If you decided to go that route, what you need to do is not dose anything for a week, test you parameters to establish a base line, then at the end of the week, see how much was used up by your corals.

Once you know that figure, you can start off slowly by using a very minimal amount in your top off water. Wait a week, then test again. You basically just keep adding more until supply meets demand.

Before you actually start kalk, you want to get your levels to where you want them. It's difficult to get it dialed in, but once you do, you just mix and let the top off pump do your dosing for you.

As always, I highly recommend reading some additional sources prior to using kalkwasser. Always best to know more than less.
 
yea you need to keep an eye on kalk tanks at first to make sure your aren't overdosing. if you over dose then your ph will spike through the roof like 11-12.:[
 
skunkmere said:
dont go to 9. maybe 8 or 7.5. magnesium is good. i think its your water change, if you dose then do a WC the alk will drop to balance with what your salt's alk is. Quit doing so many WC unless you have high nitrates or phosphates. thats why you change water, if you don't have high nutrients then just dose 2 part in equal portions. MG 1350 is a long way from 1450. to get it up to 1450 you need like a 600ml of mag supplement. 1350 is fine though. also if you go t some sps that will also eat up the extra alk you are adding, or maybe its your tank kinda buffering itself. blah blah blah.
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The Alk of the salt mix is 9dkh. I was told by a few members that I should do water changes until I reach my desired dkh then monitor how much it drops a day then start dosing. My calcium is high enough just from doing water changes so I dont see a need in dosing calcium as I only need higher alk. and isnt 1450 mag very high?
 
How are you measuring your alk? In my ample experience with tons of test kits, some of them straight up suck. At one time I though I had an alkalinity problem due to a sh**ty test kit (Sera brand). I bought a seachem test kit, used the reference sample for the test water, ran it with the Sera kit, and would'nt you know it, the Sera kit was off by 35%. The seachem one worked great, and the problem was solved, since there was no actual problem, just a crappy test kit.
 
I use the red sea test kits, took it to beyond the reef and they tested it with red sea as well and they told me the same number. I'm thinking about buying the Hannah checker for alk, but I'm still deciding if its worth pay that much $$ for it.

pacmann117 said:
How are you measuring your alk? In my ample experience with tons of test kits, some of them straight up suck. At one time I though I had an alkalinity problem due to a sh**ty test kit (Sera brand). I bought a seachem test kit, used the reference sample for the test water, ran it with the Sera kit, and would'nt you know it, the Sera kit was off by 35%. The seachem one worked great, and the problem was solved, since there was no actual problem, just a crappy test kit.
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tomek77pl said:
I use the red sea test kits, took it to beyond the reef and they tested it with red sea as well and they told me the same number. I'm thinking about buying the Hannah checker for alk, but I'm still deciding if its worth pay that much $$ for it.
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I wouldn't. Seeing that you are eliminating variables with two identical read outs from two different sources. I would think your dKH test kit measurement is accurate and reliable.

Regarding your calcium and magnesium levels, both are a tad high but should not inhibit growth as long as they are kept stable. I would not specifically dose either calcium or magnesium (other than routine water changes) until your levels reach desired numbers. I am not sure what corals you are keeping but a mature mixed tank can easily drop 1+ dKH per day (1 dkh = 8.5 grams, approx 1.8 tsp, or 0.3 oz of baked baking soda/soda ash). SPS, corraline, and to some extent macro algae such as Halimeda and even LPS corals will deplete alkalinity.

Re: Kalk - kalk is a balanced additive meaning it will add equal parts calcium and alkalinity. It is typically used to maintaining levels and balancing PH swings during non-photo periods. It is not the best option for correcting a calcium or alkalinity balance.

For your reference, here is an article about correcting alkalinity, calcium, and magnesium problems: http://www.advancedaquarist.com/2002/11/chemistry

For what its worth, there are many factors that contribute to growth rate not just water chemistry. General water quality, quality of light, water flow amounts, phosphate amounts (0 is not necessarily good as phosphate is a building block!), type of coral (the prettiest ones always seems to grow VERY slowly), and available food. If your inhabitants look healthy I wouldn't number chase (as said before). If you must, slowly change variables, and monitor corals until you reach your target levels.

Good luck.
 
You dont need a new test kit... how will you know it's accurate? If two red sea test say the same thing, then that shows good precision but not necessarily good accuracy. Doesnt matter what test kit you use, im not saying get a new one. What you need is a reference sample, a standardized solution of alkalinity, usually 7 dkh or whatever. Dirt cheap to get these, seachem would send you one for free if you called and said you were out. Guarantee it. Good test kits generally come with these to prove that they're legit, but that's not to say that your red sea kit is garbage cuz it didn't come with a reference sample.

Reference samples are a good thing to have around anyways. I've worked at a few fish stores, and none of them check to see if their test kits are correct. People get their water tested a LFS's cuz its easier than testing it yourself, not cuz of its inherent accuracy. You can get better results at home, by yourself, with any test kit and a reference sample. I'd recommend a salinity and alkalinity sample to have around. Calibrating your refractometer with the solution you are aiming to get in your reef is a good idea too. My two cents.
 
Hi guys, I apologize for not answering, I just wanted to see if my alk raises or drops. With testing for the past two days I kept a alk of 7.7dkh( tested with salifert and red sea) with dosing 50ml of the soda ash solution from BRS. Is that to much for a tank like mine? The owner from aqua pros says he doses about 10 ml for his coral tanks which kind of scares me since I'm dosing 50ml. I attached a picture of my tank so you guys know how much corals I have about 14 sps mini colonies.

Iphone pic :(
View attachment 19337
 
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