How do I raise my Alk levels

[chase33]

Over the last week or so my ALK levels have tested pretty low. I am trying to find out how to raise them. Today it tested at 5.8 DKH (2.06 MEQ/L) and has tested around that value lately. I use the Salifert test kit and have been told by Salifert that there are no problems with the kit tht I have (theyve tested it). Here are my test results taken today at 8 PM (3 hours after lights came on).
Temp = 77.9
CA = 410 PPM
ALK = 5.8 DKH, 2.06 MEQ/L
PO4 = 0.03 PPM
MG = 1250
PH = 8.4
Salinity = 1.024
Nitrate, Nitrite and Ammo = 0

I've started dosing my system last week using the two part system, Anhydrous CAC12 and Arm & Hammer Baking Soda. Reading the Chemistry calculator on Reef Central it states in order to raise my CA an ALK levels to 420 and 2.9 respectively I need to add the following:

2.9 tsp of the calcium solution &
7.9 tsp of the baking soda solution

More information:
120 gallong tank, 40 gallon sump
Approximately 200 #'s of Live Rock
Approximately 250 #'s of Sand

1. If I add the 7.9 tsp of the baking soda solution will this raise my Alk levels?
2. If yes to question 1, can I add all at same time or at what dosage?
3. What amounts of both solutions should I add to maintain adequate levels - I assume I should find out the amount of CA & ALK decreases each day before that determination can be made or am I wrong?

Hope I added all info needed. I'll test again tomorrow.

 

[Carlo]

You definitely got the idea how to do this. I ran the calculator and input tank sizes and a guess at 3/4 full sump. Input the rock and sand and came up with 116 gallons of water.

Using 116 gallons, Alk of 5.8 dKH and a desired Alk level of 9 KH (3.21 meg/L), I came up with 42.1 grams, 8.9 tsp of baking soda needed. I choose 430 as the target Calcium level which seems about balanced to me and came up with 24.4 grams, 4.8 tsp of Anhydrous Calcium needed.

9 dKH of Alk sounds a little better as the target point IMHO so I choose that instead of 8.12 dKH.

Don't add these all at once. If possible drip the solution instead of just pouring it in. Or pour small amounts into the sump throughout the day instead of all at once (that days amount, not total amount). You don't have to be anal about this but the more smaller/frequent amounts added the better as there is less overall QUICK change to the tank. It could be split up to a morning and evening dose.

To keep safe and not shock the tank or drop the pH much (will lower a little bit before rebound back to normal) only allow the tank to raise about 1 to 2 dKH a day on Alk.

If it were me I would not dose the calcium on the first day as your Alk levels are lower then the Calcium at present from an ionic balance point (compared to natural sea water). If you break up the Alk dose into 3 days worth of additions do only the Alk on the first day. Your Calcium will then pretty much match your Alkalinity levels from an ionic standpoint. Then split the Calcium dose in 2.

Don't add/drip both the Baking Soda and Calcium at the same time. Do one then the other switching back and forth. Give the tank at least an hour of circulation before switching to the other product.

It would probably be a good idea to test levels each day just to make sure things are going as planned. On the 3rd day you may even want to plug your current numbers back into the calculator and see if there is an adjusted dosage. This could be from using weights a tad bit off from real weight or having excess moisture in one or both of the products, having teaspoons that don't measure exactly 1 true teaspoon, etc... In other words there are some variables that could make your measuring not 100% "true" so don't take the advice of the calculator as "God" but more of a guideline for getting real close to intended values.

Hope that helps,
Carlo

PS 1 meg/L = 2.8 dKH so just use 2.8 as the multiplier/divider to convert.

 

[chase33]

The calculator as well as in your response says that this would lower the ph somewhat. I thought those with ph under 8.4 (those who want it to rise) would use the baking soda as opposed to the other method in the two part system. Why would it decrease the ph? Also, about how long should I wait to test after adding the solution? Thanks for providing the info about waiting 1/2 hour before adding second part (alk) after first part (calcium) or vice versa. I did have that question too. by the way, thank for your help. I often read your responses to other threads and they are very informative and helpful. I appreciate your help here and on other threads I've started and those started by others.

Thanks

 

[Carlo]

The pH will drop only a slight bit unless you dump a lot in at one time. This happens because of the amount of CO2 in baking soda. You have probably heard of washing soda/soda ash or baked baking soda (same thing) where you bake the baking soda in the oven for a period of time. This drives off the CO2 from baking soda and leaves you with washing soda/soda ash.

If you dose washing soda into the tank the pH rises very quickly because there is no CO2.

You can actually use a mix of baking soda and soda ash together to not move pH at all. It's about 6 parts BS to 1 part SA. The SA will greatly increase the pH much more then the BS will lower the pH which is why it's not a 1 to 1 mix.

You should be able to see the first change within a hour (about 90% accurate) of dosing but it will take a full day to get true results of the dose. Your pH will also be back to normal in that time frame.

If you want to know why it takes a full day I can explain it but you probably don't care. It just has to do with the change from bicarbonates to carbonates and back and forth until the tank equalizes (12-24hrs).

Your welcome!

Carlo

 

[GregW]

What are the negative effects of low KH/Alk?

 

[Carlo]

First of all "Low" is in the eye of the beholder.
Natural Sea Water tends to run at 7/8ish dKH
The general rule heard most often (I've heard anyway) is 9-11 dKH
Guys running BLU coral method run at up to 16 dHK (calcium 500+, Mg 1600)
Other who have SPS tanks run Calcium at 500 and Alk at 7/8 dKH
Others who have SPS tanks run Calcium at 400 with Alk at 11/12 dKH

Obviously there are many methods people run tanks at and some are quite impressive. It's sort of like "pick your poison"

The one common thing you typically notice is all run at NSW or higher levels. Typically the same for Calcium. The reason is that we have enclosed environments and we don't have the vast sea to replenish our systems. Knowing the update of both Calcium and Alkalinity the general idea is to boost these levels higher then NSW so there is a "buffer zone". If you boost alk to 11 dHK and don't happen to dose for a few days/week the level might only drop to 8 dKH (every tank is different) but you are still in a "good zone" and dose it back up. Had this same system only been run at 8 and dropped off to 5 (3 dKH drop) calcification would be problematic and you might/probably have issues with your corals.

So what is low? By most standards I'd think the answer would be 8 dKH (with 7 just getting by, but still usually safe).

The one caveat generally excepted is that if you have a low pH of say 7.9-8.1 you are better off keeping Alk on the high side. The low pH inhibits calcification and other processes so keeping both carbonates (Alk) and Calcium on the high side MAY allow the corals to get to these items easier.

Carlo

PS If you were going to ask I run mine between 8-10 dKH with no apparent difference in growth or anything else.

 

[GregW]

Thanks Carlo.

So I guess 1.71 is not good I've never tested the Alk before since everything seemed to be OK but growth has never been as fast as other's that I've talked to. It is a Salifert test kit so I'm going to have the water tested at a lfs tomorrow. But other than slow growth is there any other problems one would expect with low KH/Alk?

 

[chase33]

Thanks for the info and help. I'll let you know how it turns out in a few days.

 

[Carlo]

Thanks Carlo.

So I guess 1.71 is not good I've never tested the Alk before since everything seemed to be OK but growth has never been as fast as other's that I've talked to. It is a Salifert test kit so I'm going to have the water tested at a lfs tomorrow. But other than slow growth is there any other problems one would expect with low KH/Alk?

Just to clarify something IMPORTANT. You quoted 1.71 which I'm sure is in meg/L. What I mentioned is dKH which is a German measurement. You can convert meg/L to dKH by multiplying by 2.8. So 1.71 meg/L of alk is the same thing as 4.788 dKH. While it's still way low it's a lot better then 1.71.

I don't have a lot of confidence in Salifert test kits these days. There is way to much difference from batch to batch and there has been kits that are way off (dangerous levels). I personally like and recommend the API test kits. They are among the cheaper kits and just plain work. Fill vial with 5ml of water to the line. Then drip the solution in one drop at a time until the color changes. Each drop = 1 dKH. Doesn't get easier then that.

Carlo

 

[Boomer]

If you dose washing soda into the tank the pH rises very quickly because there is no CO2.

This is often a misleading a myth. When ever you add either you raise the CO2. For each eq of HCO3- you add 1 eq of Alk and 1 eq of CO2. When it is CO3-- you also add one eq of CO2 but 2 eq of Alk. When ever you raise the Alk there is ALWAYS and increase in CO2. There has to be , as in Dick & Jane terms pH = Alk x CO2. Example and to make it simple we will assume there is not B Alk.

pH = 8.3
Alk = 2.5 meq/ l

CO2 = 0.41 ppm

pH = 8.3
Alk = 3.0 meq/ l

CO2 = 0.50 ppm

pH = 8.3
Alk = 4 meq/ l

CO2 = 0.66 ppm

I also, at this time wold not be raise your Alk any higher than 2.75 meq / l. If you go to 3.2 or even much over 3 you are at a Ώ = 6, which is where abiotic precip starts. Let the pH get down first to 8.2 - 8.3. As far as running the Ca++ or Mg++ up to higher levels than NSW I would not. Nothing says they grow better with Ca++ any higher than 360 ppm C a++. The Blue method is another issue and not this tank. And low Mg++ levels it will inhibit the ability to keep Ca++ up, as it shifts Ώ value to a lower level of abiotic precip.

 

[Carlo]

I wouldn't say it's a myth or misleading, just not the whole story. We bake the baking soda to drive off the inital CO2 from the baking soda to get washing soda/soda ash/baked baking soda (call it what you will). When you initially dose the washing soda it will raise the pH very quickly no question about that. The pH & CO2 will later adjust themselves to be the same regardless of if you add carbonates or bicarbonates.

Carlo

 

[Boomer]

The pH & CO2 will later adjust themselves to be the same regardless of if you add carbonates or bicarbonates.

Granted to a point but that later can be days if it is SA, as it also raises the Alk higher than BS ( a least the way most do it by not looking a weight or Mol values. Even if we go by mol values there is a differnace ( see below). A higher Alk will lower the effect of pH drop with CO2 additon or increase ( do not confuse this with "CO2 has no effect on Alk or vise versa"). This is why we try to tell people to stay away from straight SA unless there is both a low pH and Alk issue. So, it in real terms, it does make a diffence which one is added.


From Randy
Supplement Initial pH....... 24 hour pH......120 hour pH (5 days)
none................8.10......... 8.11...........8.21
0.5 meq/L HCO3-.8.06......... 8.15...........8.33
0.5 meq/L CO3--..8.44..........8.28...........8.34
0.5 meq/L OH-....8.76..........8.47...........8.33
0.5 meq/L H+.....6.91..........7.91...........8.15

 

[Carlo]

I'm not sure what any of this has to do with chase33 getting his alk raised up a bit. Only NaHCO3 (sodium bicarbonate/baking soda) was suggested to be dosed, not Na2CO3 (Sodium carbonate/soda ash). Really the only mention of the soda ash was that it could be added to the mix at roughly 6:1 to not have as much pH shift when dosed. This wasn't really even suggested for chase33 to do so I'm sure why we're even talking about it.

Concerning the Omega, with a pH of around 8.4 and Calcium of 410 wouldn't it take the Alk to 4.2 ish meq/L (11.7 ish dKH) to hit that Omega mentioned in the previous post?

Carlo

PS I thought you didn't want to knit-pick posts?

 

[Boomer]

You brought it up in your post If you dose washing soda into the tank the pH rises very quickly because there is no CO2.

This is not knit picking. I tried to bring you to the next level. There is CO2 unless the pH is above 9.1, with a normal Alk. At pH 9.1 it is ~ 50/50 HCO3 - and CO3-- and at pH 6.0 it is ~50/50 CO2/H2CO3 and HCO3- based on pHnsw

wouldn't it take the Alk to 4.2 ish meq

Yes, that is correct it is more like ~4.2 meq/ in a Aragonite forming environment. But can be shifted lower buy low Mg++ and with his parameters maybe more like ~ 4. It also depends on whether it is Calcite or Aragonite forming. Aragonite could care less about Mg++. Something Randy and I were going to look into but never did. What is that precip Aragonite or Calcite ? Aragonite forms at higher pH's than Calcite. Omega values are based on pure mathematics or in a controlled environment something a reef is not so I like to keep it lower. And temp also plays a roll as do ion-pairs. It is me lowering the level so one does not push things to that more real level. I do not want to be telling people yeah, go to 4.2 meq / l cause the math says so and why I posted a "scare tactic" of 3 meq/l

 

[Carlo]

Got ya on the washing soda. It was just in passing but not what was recommended to the person to use. Don't need to get into the CO2 here but maybe I'll start a new thread with it.

I agree on the Omega depending on aragonite versus calcite forming but generally don't see precip happening at the lower levels in most aquariums with a normal Mg level. I generally don't like alk levels that high myself but it does seem a lot of people run 8.4 pH, 400+ Ca, 11 dKH Alk, 1250+ Mg and don't run into any sort of problems. I'd almost wager that most people use these as a target values.

Out of curiosity Boomer, what are your target numbers you try and keep your tank nailed at?

Carlo

 

[Boomer]

You must have missed my sig on RC I no longer have tanks. 35 years was long enough I like keeping things near NSW maybe with a slight increase in Alk to 3-4 Meq /l if the pH is in line.

lot of people run 8.4 pH, 400+ Ca, 11 dKH Alk, 1250+ Mg..........I'd almost wager that most people use these as a target values.

I will have to disagree to a point. I have seen very, very few with a pH of 8.4 or Ca++ at or near 400 based on polls. pH's are usually low 8's and often high 7's and many run Ca++ much higher than 400, like 425- 450. Most do seem to be set on the Alk though of 11 dKH but I would rather see it lower like ~ 8.5 dKH. However, the values you gave would be a good goal IMHO. Although NSW is 1300 ppm Mg++ being 50 ppm less is not really an issue or worth debating unless one is into some of the so called "exotic methods" i.e Blue Method and I wonder if they really need it. IMHO coral reef parmeters are just fine and Mother Nature seems to know more than us.

 

[Carlo]

That should have said "strive to run at 8.4 pH, 400+ Ca, 11 dKH Alk, 1250+ Mg" meaning for their target values. I typically see 8.2-8.4 target for pH, typically 400-440 for Ca, 1250-1350 for Mg but it seems 11 dKH is the "magic" Alk number.

I'm with you on the Alk of 8.5. I like keeping it right at or between 8 and 9 with it hitting 7 fine. I'm more of a 400 Ca guy also with 380 being fine. I'll bet we differ on pH values we like to strive for though. I'm a fan of keeping it on the higher side between 8.4-8.5 on my tanks. I'm aware of potential issues with higher pH but not a problem on my systems. I sort of agree with Anthony Calfo on pH ranges although he likes 8.3-8.6 and would prefer it on the higher side of that range. What's your take on pH Boomer?

Also since you mentioned coral reef params being just fine. What's your take on temperature? I like to vary mine monthly (via ACIII - small daily changes actually) to match what they get in the wild with a cap at 84 and 78 for highs and lows. Have you ever experimented with changing temps like in the wild or did you just prefer to stick the temp at a certain point on your tanks?

Thanks,
Carlo

 

[Boomer]

I often disagree with some of Antony's chemistry issues as does Randy. I like 8.2 - 8.4. There is no sound reason to have it at 8.6 and many may have issues with Ca++ precip if they let the Alk or Ca++ get up. Unless of course one is trying to control Dino's or say Bryo for a couple of wks. And maybe if there are no issues the Antony range may be OK and you may have less unwanted algae problems. However, think of that Omega value, you are limited to a Ca++ of around 410 and Alk not above 2.5 @ pH 8.7 You are asking for trouble and you need think of how much noise is there may be in those test kits and meter. I pretty much agree with Randy's parameters. You need a safe buffer zone and not push things to the end, especially when no body can give me **a reason** to do so. I might add I have less issue with those high pH's if they are brought about by kalk, as opposed to some buffer which often jacks-up the Alk.

Your temp range is fine but 84 is pushing it. You may not believe this but a many years ago we had a rare heat wave for two days, +100 F. My tanks were @ 98 F and was still in the high 80's 4 days later. I lost nothing but I had no SPS's either. I think for us but not so for a coral reef, the temp may not be as big an issue as it is usually short lived, unlike the reefs where it is much more constant and a yearly increase of 2 F over std temps can kill things. Of coruse there are pieces of some reefs that can get high when the tide is out and they are stuck in a pool. Same for Salinity being high or low, depending if that pool gets a lot of rain or not, or high evap. But again these are short lived.


Reef Aquarium Water Parameters
http://www.reefkeeping.com/issues/2004-05/rhf/index.php

 

[Carlo]

I thought you might disagree with Anthony but just wanted to get your own opinion. I knew where Randy stands on it and kind of figured you would be similar. I kind of get the impression you like the Ca and Alk a little lower then Randy however (maybe wrong). Maybe I shouldn't say "like" but don't see a problem with them being closer to NSW where it appears Randy prefers things a bit higher.

Anthony contends that 8.2 is average sea pH but not what is found on the reefs around Fiji/Tonga (where many/most of our corals come from). He says the values are in the range of 8.3-8.6. Does this reef pH go with your understanding of the common pH found there?

I tried running at about 8.55 but have backed it down to around 8.45 (pretty constant). Even when my system was high I was able to hold Calc at 500 to 520, Mg at 1350 with Alk levels of 13, temp 82 and still didn't see any precip (had to play). I kept pushing to see where the boundary was in real life and not on paper or in an aquasion. I didn't push farther then that since I didn't want to risk it further. I did keep the levels there for a good solid month at 8.55. Nitrates/phosphates at 0.

Trying to find/research why I could do this I came across the BLU Coral method. The guys running this tend to run things even higher then I did and they don't get precip either from what I've read. I'm sure many have failed trying to get to those levels and we just don't read about it. What's your thought on how these values can run so high?

I'm not a believer that 84 causes problems if you have good O2 exchange and it's not a sudden change to 84 but gradual. I know I can run 86 for long periods without problems but start loosing SPS when I get into the 87/88 range for a day or two. I've been trying to model the temps (but I do cap them at 84 for a little safety) after this:

In Fiji it appears the average gets to 85 and 86 a few months of the year. Granted our tanks aren't reefs so I cap it at 84.

Carlo

 

[Boomer]

Randy likes higher levels not because they are needed but to act as buffer for lazy people so to speak. I might add he also thinks it is OK to have somewhat large pH swings and says a constant pH may not be a good thing, where I also disagree. My ranges are just a little narrower but are still with in his guide lines.

He says the values are in the range of 8.3-8.6. Does this reef pH go with your understanding of the common pH found there?

That is not impossible and they could also be lower than 8, it depends on where they were took, at what time of the day and year and surrounding input. The ocean pH is from 8.0 - 8.3 but that does not mean that some piece of the ocean can not be higher or lower. We could go find another reef where it is much lower in pH. I have not seen a pH profile of the Fiji's and if I was to ask someone it would only be Walt Smith, since he has lived there for more than 2 decades. I talked and was with Walt Smith at Kevin's house after the F & S frag swap and he told me when Anthony was there he never even got in the water. So I don't know how or where he got those numbers. I have never heard of any coral reef having pH's as high as 8.6 accept in lagoons. In a open coral reef it can't happen. Feel free to show one. Most reefs in Australia do not even get above 8.2. Matter of fact if you look into some seawater chemical oceanography books, manuals or articles the pH:Alk: pCO2 plots do not even go to a pH of 8.3 but more like 8.25


As far as running the temps up to 84, in 2000 large portions of the Fiji's exceeded their MMM : 83.3 F for five months, remained above 84 for 3.5 months and peaked at 86-87 in March and early April. This caused massive bleaching and the Fiji's have had a few episodes of this in the last few years, so I would no be going off of any Fiji's plot like you posted for sure, at least not for my tank or anyone else. It makes no sense. Good Circulation or not the O2 is lower at these higher temps and does nothing for marine life but stress them out. And that high temp does not benefit them. Therefore what is the reason, when there is none, unless all animals in that tank are form Fiji and we know what temps they like and don't like.

Other reefs can have higher temp's but the animals become accustomed, it is part of their nature on "their" reef and when there are large changes they do not like it when they are use to small changes. Animals and plants are best adapted to their own reef is what I'm saying and not some other reef. For example, IIRC Belize water temps are higher than Fiji's but no bleaching at the temps see on the Fiji's. And we really don't know where allot of these animal come form. We are just told were they come from. This is why I like to keep things in a lower or narrower range or more of a coral reef avg so to speak, rather than shooting for max.

The same argument for chronically high Alk or Ca++ as pH, there is no reason. If one can get away with it so what. At times one can often get way with things. Why put something in a position to maybe bite you when there is no reason to do so. Just because I put a bullet in my 357 mag and spins the cylinder 50 times and do not end up with a bullet in my head does not mean it is OK, as I did it and nothing happened. . That is all a very poor argument. And not that is not OK to have some fluctuation in a reef tank like a coal reef. That is fine, reefs are not constant.