Low Alk

[cmart28]

My Alk is between 6.7 - 7 dkh. My tank has been up for 3 months and my Alk and my Alk has always been between 9 - 9.6. The only thing I can think of is that I am on my second batch of Salt, Tropic Marin. I am using Salifert test kits. All other parameters are fine, Calcium - 425PPM, Mag - 1305, ph - 8.2. Nitrate - 0, Phos - 0. I have a few small LPS and Soft Corals, I also have a few small SPS frags, everything is doing great. My coraline growth algae I notice more and more each week. I read one of Randy's articles suggesting adding Baking Soda, but I wanted to check here first.

[tonyscoots84]

u have to dissolve the baking soda in rodi as per what measurements randy has on his 2 part diy page and use the reef calculator as a guide to figure out how much to dose......

2 part DIY link

http://reefkeeping.com/issues/2006-02/rhf/index.php

Reef Chemistry Calculator
(rememba if your looking at dkh u have to change over the meq/l button to dkh so u can get the correct dosage to raise it to ur desired level)

http://reef.diesyst.com/

[jdieck]

Tropic Marin Salt is usually in the low side of the alkalinity recommended level so you may need to adjust its level before a water change.
Also check it's level of Calcium. Tropic Marin Pro has normal Calcium level but Tropic Marin will not and may also need to be adjusted.

[cmart28]

I will give that a try tonight. I am using TM Pro and my calcium levels have always been between 405 - 430PPM. Would you recommend a better salt that has consistent levels between Alk, Calc and MG? What I don't understand is why it has dropped from around 9.6 to 6.7 in a few weeks, any ideas?

[jdieck]

<a href=showthread.php?s=&postid=9189214#post9189214 target=_blank>Originally posted</a> by cmart28
I will give that a try tonight. I am using TM Pro and my calcium levels have always been between 405 - 430PPM. Would you recommend a better salt that has consistent levels between Alk, Calc and MG? What I don't understand is why it has dropped from around 9.6 to 6.7 in a few weeks, any ideas?
Alkalinity is continuously consummed by corals and coralline algae in established tanks and by the nitrification process in new tanks so continued addition of an Alkalinity supplement (as well as Calcium supplement) is required.
An established tank can consume in the order of 0.5 to 1 dkh per day, some sps coral loaded tanks can consum up to 2 dKh per day.
Tropic Marin Pro is a good salt although its alkalinity content is relatively low.
I have tried Tropic marin, Tropic Marin Pro, Instant Ocean, Oceanic and Reef Crystals.
The only one that in my experience does not require supplementation before a water change if prepared at a salinity of Natural Sea water (1.026) is Reef Crystals.

[cmart28]

Thanks jdieck, maybe my next batch of salt I will try Reef Crystals, I know many people that prefer Reef Crystals to TM Pro.

[cmart28]

A few more questions, I read the 2 part DIY article and it says to dose .4/ML of the Alk solution, but the calculator says to bring my Alk up to 9 dkh I need 5.1 tsp. of Baking Soda. The 2 part DIY article says I think mix 2 1/2 cups of Baking Soda, just not sure of the process here. I know that I can use the 2 part DIY Alk after I get my Alk to 9 dkh, but to bring the Alk up to 9 I don't know where to start. Also .4/ML seems like an extremely small amount, would I use a syringe, like the type that comes with Salifert test kits? Thanks in advance.

[jdieck]

<a href=showthread.php?s=&postid=9201961#post9201961 target=_blank>Originally posted</a> by cmart28
A few more questions, I read the 2 part DIY article and it says to dose .4/ML of the Alk solution, but the calculator says to bring my Alk up to 9 dkh I need 5.1 tsp. of Baking Soda. The 2 part DIY article says I think mix 2 1/2 cups of Baking Soda, just not sure of the process here. I know that I can use the 2 part DIY Alk after I get my Alk to 9 dkh, but to bring the Alk up to 9 I don't know where to start. Also .4/ML seems like an extremely small amount, would I use a syringe, like the type that comes with Salifert test kits? Thanks in advance.
A dose to make the adjustment and a dose for replenishment are two different quantities.
The recommended dose for adjustment you can get from the calculator. You can select from the calculator to use either Baking Soda (The powder) and it will give you the amount of powder you need to dissolve in a cup or two of RO/DI before adding it to the tank or you can also select Randy's formula for the adjustment and the calculator will also tell you the amount of liquid of the alkalinity part you will need to add to make the adjustment.

For maintenance purposes the article suggest a start up quantity that has to be adjusted according to the trened shown by your subsequent tests, If it starts dropping you need to increase the maintenance amount of both parts, If alkalinity is increasing then you need to reduce the maintanance amount.
The start up amount recommended in your case will be 0.4 ml/gal/day.
in oher words as an example if your system has 55 gallons of aquarium water then the amount to add each day of each part will be 0.4 times 55 or 22ml which is aproximately 4 and 1/4 teaspoons of supplement.
If you tank system water volume is 20 gallons then you need a daily dose of 8 ml (20 x 0.4) and so on.
So adjust the maintenance dose to whatever your system water volume is by multiplying the recommended dose per gallon (0.4) by the number of gallons.
If you do not relly know how much water your system holds you can use the following calculator to aproximate the volume:
http://home.comcast.net/~jdieck1/volcalc.html

Enjoy!

[mcurl98]

jdieck- I have been trying to raise my alk using the Kent product and the calculator. I am using what I read to be the max--70 ml which is one half ml per system volume (140gallons). I do this twice a day (every 12 hours)This increases my alk by one and raises the ph by .1. My tank uses 1+ dkh a day even with the reactor so I am making no headway in increasing the alk. My CA is 400, PH about 8.3 and magnesium is slightly over 1200. If I switch to baking soda can I be more aggressive in trying to raise it. The calculator says 9.7 tsps of soda. How much do you think I could put in at once? I am trying to bump the alk to 11 as my tank seems to be better off when my alk is higher. I have mainly SPS. Thanks.

[jdieck]

<a href=showthread.php?s=&postid=9202635#post9202635 target=_blank>Originally posted</a> by mcurl98
jdieck- I have been trying to raise my alk using the Kent product and the calculator. I am using what I read to be the max--70 ml which is one half ml per system volume (140gallons). I do this twice a day (every 12 hours)This increases my alk by one and raises the ph by .1. My tank uses 1+ dkh a day even with the reactor so I am making no headway in increasing the alk. My CA is 400, PH about 8.3 and magnesium is slightly over 1200. If I switch to baking soda can I be more aggressive in trying to raise it. The calculator says 9.7 tsps of soda. How much do you think I could put in at once? I am trying to bump the alk to 11 as my tank seems to be better off when my alk is higher. I have mainly SPS. Thanks.
Yes you can use baking soda.
I would use up to 5 teaspoons every addition. 5 teaspoond will increase your alkalinity by about 1.5 dKh every time.
Remember that you need to dissolve it in RO/DI before adding it.

Also take note that increasing alkalinity will also increase the consumption so your normal daily supplementation might have to be increased to maintain that level.

Is your reactor undersized? What kind of reactor is it?

[cmart28]

Again jdieck thanks for all your help.

[jdieck]

:thumbsup:

[mcurl98]

It's a Korallin 1500 and I subscribe and have spent a lot of time on your thread. I use a controller in a small effluent cup. I just lowered the PH on the controller to 6.5 with ARM. Due to using a cup, this will probably allow the PH to dip as low as 6.4 in the reactor. I know ARM is supposed to dissolve at a higher PH but I can't get the effluent above 25 at higher PHs. I increased the drip quite a bit and that doesn't seem to help either. I slowed the drip rate and lowered the PH. This should bring the effluent back up to about 35 which will hopefully help.

[jdieck]

Having an effluent at 25 is not a problem if you are adding the required alkalinity (or the maximum) say an effluent of 30 ml at 35 dKh (30x35) will add the same alkalinity as 42 ml at 25 dKh. (42x25) Here the idea is to play with the effluent to see if you can maximize that ratio, say 40 ml at 28 dkH will be more than the previous two.
I will nor worry about the PH as low as 6.4 in the cup, that is OK.

[mcurl98]

I'll keep playing with it. I've heard so much about ARM turning to mud that I've been hesitant to go too low on the PH. Thanks for your help.

[jdieck]

<a href=showthread.php?s=&postid=9203343#post9203343 target=_blank>Originally posted</a> by mcurl98
I'll keep playing with it. I've heard so much about ARM turning to mud that I've been hesitant to go too low on the PH. Thanks for your help.
Keep in mind that as the media dissolves the grains become smaller and smaller so at certain point there will be small particles.
In a downflow reactor those particles stay in the reactor, in an upflow some will leave the reactor.
In any case sooner or later the media has to be taken out, rinsed, put back and top off.

[cmart28]

I raised my Alk up to 8.4 by mixing the baking soda with RO/DI. I am going to slowly increase it up to around 9. I made a new batch of salt using TM Pro and I tested the Alk, it was less than 6 dkh, I have the salinity at 1.026, is TM Pro noramally this low?

[jdieck]

<a href=showthread.php?s=&postid=9211737#post9211737 target=_blank>Originally posted</a> by cmart28
I raised my Alk up to 8.4 by mixing the baking soda with RO/DI. I am going to slowly increase it up to around 9. I made a new batch of salt using TM Pro and I tested the Alk, it was less than 6 dkh, I have the salinity at 1.026, is TM Pro noramally this low?
It is usually around 7 so it is within the norm.

[mcurl98]

So, yesterday, throughout the day and evening, I used baking soda and got my Alk up to about 10.5. I tested it this morning and it is back down to just below 8. I'm at a loss. I've never had trouble with Alk, in fact, I usually have to watch it to make sure it doesn't get past 12. Several weeks ago, I started dosing a Kalk slurry to increase my PH in an effort to control dinos. During that time, I shut down the CA reactor so I wouldn't have anything possibly depressing the PH. It has been back on for 10 days and the Alk just won't stay up. My Calcium is around 380-400 and that won't stay higher either. I am still dosing a slurry of Kalk for the PH and it seem as though it needs more dosing to raise the PH than it has previously. I turned the flow down on the reactor to get 39 dkh at about 6.3 ml. The flow had been much higher (at 25dkh) but that wasn't doing anything either. I did a fairly large water change with TM pro a week ago and, based on the above, that didn't help. The tank is really out of whack and I'm out of ideas. While I have about 10 SPS in the tank, they are mostly small frags. Don't think I could be using dkh that fast.

[mcurl98]

I turbed off the Kalk as for some reason the tank now needs way to much of the slurry to raise PH. My PH is down to 8 and my Alk remains at just under 8. I dosed 1/2 ml per gallon of Kent's this morning. It raised the PH about .03. I'll test the Alk tonight but don't expect any movement. I upped the flow on the reactor as well.

[Randy Holmes-Farley]

I used baking soda and got my Alk up to about 10.5. I tested it this morning and it is back down to just below 8.

Why can't that just be the demand in the tank? Most people supplement alkalinity every day.

If magnesium is OK, the pH is not excessively high,a and there is not apparent precipitate on objects like heaters, pumps, etc, then I expect it is just the demand in the tank.

[eskymick]

To tag along with this thread ...

Is it typical (or acceptable) for the alk demand to be considerably different than the Calc demand ? I have a similar situation to cmart28 ... it's fairly easy to maintain the calc paramater (at 440ppm in my case), but if I dose the alk at the same dose rate (40 ml/day) as calc my alk drops from 4.0 meg/L to 3.3 meg/L overnight. I'm finding it difficult to maintain the alk in balance with the calc.

[Randy Holmes-Farley]

Is it typical (or acceptable) for the alk demand to be considerably different than the Calc demand ?

No, but usually that is just an illusion,and it actually is balanced. Alkalinity always drops faster, on a percentage basis, when not supplementing enough.

I would just dose more of both parts to maintain alkalinity. If calcium actually rises too high, then back off, but not before. It just does not respond very fast to underdosing.

I discuss that here:

When Do Calcium and Alkalinity Demand Not Exactly Balance?
http://reefkeeping.com/issues/2004-12/rhf/index.htm

[mcurl98]

So, you think going from 10.5 to 8 overnight could be tank demand? I do have quite a bit of precipitation but I've assumed that was from the Kalk slurring I've been dosing to keep the PH up. My Alk has always been steady with the reactor (at about 11). I have added some SPS frags and the coralline is more extensive but it seems like a huge change in keeping my Alk up. I did change the media in my reactor about 30 days ago (same brand from the same container). The tank has been running for about 9 months.

[Randy Holmes-Farley]

So, you think going from 10.5 to 8 overnight could be tank demand?

Depends on what is in your tank, but that is within the normal limits that folks observe. The point is, whether it is use by corals and coralline algae, or abiotic precipitation of calcium carbonate, it still sues a balanced amount of calcium nd alkalinity. There are not other big short term sinks for either one.

I have added some SPS frags and the coralline is more extensive but it seems like a huge change in keeping my Alk up.

SPS and coralline will do that. :)

You might want to increase the CO2 addition rate. :)

[mcurl98]

ok, thanks for your help. I'll keep working at it.

[Randy Holmes-Farley]

:thumbsup:

Good luck. :)