Low Alk - what to do?

FishyReef

FishyReef

Broke Reefer!
A few of my zoos have looked increasingly bad the past few days, and today my 2 acan colonies were shrunken. Tested my water this afternoon and my alk is pretty low. What can I do to increase it, and how long do I have to do so before I start losing stuff?

Ammonia/nitrite/nitrate = 0
pH = 8.25
Salinity = 1.025
Calc = 425
Mag = 1250 (I think - the water color turned blue at this mark - not quite as blue as the color on the paper, but it didn't turn any bluer despite additional drops after the 1250 mark)
Alk (from my basic test kit) = 2 meq/L
Total Alk (from advanced kit) = just under 2 meq/L
Borate Alk (from advanced kit) = 0.5 meq/L
Carbonate Alk (from advanced kit) = just under 1.5 meq/L

I haven't tested my water after making it up but will do so tonight. I also haven't rolled the bucket, but again will do so tonight. I'm using Seachem Reef Salt, and SeaChem test kits (basic, calcium, and mag/borate/carbonate/alk)

Can someone point me in the right direction?

Thanks!
 
It could be due to a significant build up of organic waste and carbon forms in the water. Some might not register in the Ammonia/Nitrite/Nitrate readings.
Higher carbon/acid contents in the tank increases the potential for the natural buffers to be overwhelmed.
Your current water change regimen might not be keeping up with the bioload.
 
fastrd400 said:
When you are mixing your new salt water, what pump do you use, and for how long do you let it mix?
Click to expand...

I honestly don't use a pump. I make several 5g buckets at a time, stir them with a paint stick, let them sit overnight, stir them again, test the salinity and add more if needed. Then usually use them for a water change within the next few days. I do get some precipitate at the bottom of the buckets but not a huge amount. I just don't have enough extra pumps or outlets to run pumps on 6 buckets at a time - and since I'm hauling them down 2 flights of stairs, into my car, and taking them to my office I really can't make a larger batch such as a trash bin full at once.

RockStacker said:
It could be due to a significant build up of organic waste and carbon forms in the water. Some might not register in the Ammonia/Nitrite/Nitrate readings.
Higher carbon/acid contents in the tank increases the potential for the natural buffers to be overwhelmed.
Your current water change regimen might not be keeping up with the bioload.
Click to expand...

Its possible, but I'm skeptical for a few reasons - I'm near capacity but not fully stocked, and haven't increased feeding regimen despite new fish (I feed 1 cube of frozen every 2-3 days). If there were more acidic compounds in my water, wouldn't my pH be low? The only thing that leads me to say its possible is that I ran out of the regular cubes and have been feeding small chunks off a block that my LFS made up that is supposed to be like Rods - I have a feeling it has a higher concentration of phosphates than other foods - but its only been the last 2 feedings that I've used it, and I haven't seen any excess algae growth.

I'm also changing between 10-15% per week of my water.

I am only a few water changes in to a new bucket of salt, so perhaps I need to really roll the bucket around?

Is there anything I can do in the short term to get my alk up without sending my other levels out of whack?
 
Other than dosing 2 part, or even alk, no. You may want to look into a 2 part dosing system, like what BRS offers, or something like B-Ionic which you can get from your LFS.

I would also suggest running the same tests on a batch of fresh salt water, straight out of the bucket/jug/barrel,
 
heres something you can read about dosing pickling lime. when dosing it'll raise your PH and cal i believe. when you add it to your water it'll have a PH of 16 so you have to dose it very slowly. i know 6 ppl doing it on a local forum(i'm going to start once i get the a doser) and its working great for them. there coral have grown better too. just beware its some strong stuff and make sure you do a lot of reading on it.
What Your Grandmother Never Told You About Lime by Randy Holmes-Farley - Reefkeeping.com
 
Dosing kalkwasser / lime (when done properly) will increase calcium but it will not raise alkalinity.
It will assist in preventing an alkalinity drop via buffering but if you have low alkalinity to begin with, you will still need to dose a product that raises alkalinity.
Usually this would be in the form of the #2 product of a Two-Part calcium-alkalinity dosing combo.
 
RockStacker said:
Dosing kalkwasser / lime (when done properly) will increase calcium but it will not raise alkalinity.
It will assist in preventing an alkalinity drop via buffering but if you have low alkalinity to begin with, you will still need to dose a product that raises alkalinity.
Usually this would be in the form of the #2 product of a Two-Part calcium-alkalinity dosing combo.
Click to expand...

Yeah, that was my concern in dosing kalk or 2-part. My other parameters are within acceptable limits, its just the alk that is low and if I dose everything then there will still be an imbalance. I'd spent some time last night reading up on options, and came across one article that suggested using baking soda (Chemistry And The Aquarium: Solving Calcium And Alkalinity Problems — Advanced Aquarist | Aquarist Magazine and Blog). I'm going to try a small amount today based on the instructions in the article and see if I can raise it a bit - I plan to do this *very* carefully because I know any swing in alk can be problematic, and I don't want it to precipitate out into my system. Before I try this, has anyone heard anything bad about going this route?


My hope is to get the balance right again, and then worry about dosing 2-part. I'm guessing the problem arose from new bucket of salt and hope the imbalance corrects itself in freshly made water after I roll the bucket around a few times. But I am going to need to start dosing my tank at some point as I'm getting more and more sps corals in there!
 
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Used the baking soda method and raised the alk by about 0.5meq/l, (so my tank is now at 2.5meq/l). pH is currently at 8.1-8.2. One acan colony is super pissed but everything else looks unchanged after the dosing. Hoping that things look better tomorrow.
 
What tank is this on? And how much water are you changing?

I am struggling to understand how your tank can test at 2.0meq/L or 5.6dKH, when you are using a salt that mixes at a rate of 4.0–5.0 meq/L or 11.2 - 14.0 dKH.

I am thinking there is something going wrong at some point.
 
This is on my 90g, which has about 105g total water volume with the 20g sump (not filled to the top). I too am having a hard time understanding since only the alk is out of whack. I've tested using 2 separate kits, and tested again after dosing today so know yesterday's readings were correct. In the past my alk has always tested on the higher end of the spectrum (around 11-13 dkh). I thought I'd have time to make water last night but didn't, so will definitely do so tonight and test my freshly made water. I only change out 10-15g per week (last week it was 10g), and I'm due for a water change tomorrow. What would use alk only but not change pH, calc, mag, etc.?

EDIT: One other thought - I did some large water changes about 4-6 weeks or so ago when they cleaned the carpets in my office and used water from the LFS - I don't know what salt mix they use and didn't test it, but over a week I changed out about 60% of my water. Its possible that the alk was much lower in that water, though I think I would have noticed a drastic change in my pH or coral behavior that I really didn't notice (aside from what I saw in response to the VOCs from the carpet cleaning - everything improved with the water change though rather than reacting as if alk had drastically changed). I honestly didn't test alk then because I didn't see anything that led me to think something was off....
 
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Here is a response from Larry (ccCapt) from a couple years ago:

The best supplement to use to raise alk is Arm & Hammer baking soda. Alk gets used up, in a set ratio along with calcium and magnesium, in the calcification process. That process uses aprox 2.5 dKH alk for every 18 ppm calcium and 2 ppm magnesium. So if your system has the need for dosing alk, it also has the need for dosing calcium and magnesium. Alkalinity will only drop if it's being used up in the calcification process, if you water chemistry gets out of whack and you get a precipitation event in your system, or if you do water changes with a salt that has a lower alk level than your system.

This article should answer any other questions you may have.
A Simplified Guide to the Relationship Between Calcium, Alkalinity, Magnesium and pH by Randy Holmes-Farley - Reefkeeping.com
 
Thanks Wade - that article is by the same author as the article I found and linked to earlier, and Arm and Hammer baking soda is what I went with. Still doesn't explain why my alk is low relative to my calcium, but hopefully that's a salt bucket issue that will resolve itself (ro/di is running as I type :)
 
I'm wondering if my alk could be precipitating out in my water change buckets? I've got a nice white build up going on the bottom of my buckets that I can't seem to easily remove. I rinse the buckets every time before I refill them with RODi water, and once tried a vinegar soak, but it didn't seem to do much good. My understanding is that alk and calc bind and precipitate out in the absense of enough magnesium, and will continue to do so. If I've got calcium carbonate that has precipitated out in the bottom of my buckets, could those molecules continue to pull alk out of my newly made water? Even though my mag levels look okay, if there's already calcium carbonate in higher concentrations in my buckets, then that would make the mag low in the new water relative to how much calcium, alk, and calc carbonate would be in the buckets. Just another random hypothesis that I had in trying to figure out what's going on....
 
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So the residue in my buckets is definitely calcium carbonate that has precipitated out of my water column. I just cleaned out the dish that I had mixed the baking soda with a little tank water in yesterday and it is totally covered in the same white film that is really hard to rub off. All this time I've been thinking that it was a salt residue on the bottom - never occurred to me that it was calcium and alk precipitating out of the water column.

Last night I did buy new buckets and made up 4 batches of water - one old bucket and one new bucket with salt from the bucket prior to rolling; and one old bucket and one new bucket after rolling the salt bucket. I wanted to see if it was the residue on the bottom of the old buckets pulling alk out of newly made water, or if it was the unrolled bucket. I will test all 4 buckets when I get home tonight and let you know what I find!

In the mean time, is there anything I can use to get this hard white film out of my buckets?
 
Update: Sooo, I bought new buckets and made 4 buckets of water - two with new buckets, two with old buckets. I used the salt as is for one old and one new bucket, then rolled the salt bucket and used the newly rolled salt for one new bucket and one old bucket. Let it sit for a day, made sure salinity was identical in all 4 buckets (1.025) and tested the alk. It was 3.0 meq/L in all buckets. Then I made a 5th bucket of water, added the salt, and mixed it with a powerhead for 3 hours. Let it then sit for a day, tested the alk, and it was also 3.0 meq/l.

Meanwhile, I've been adding baking soda dissolved in water into my tank at work to bring the alk up just from 2.0 to 2.5 meq/L, and it keeps dropping back down to 2.0. At this point I've concluded that (a) either my test kits are bad or (b) the bucket of salt is low in alk.

I'm guessing the alk in the tank keeps dropping back down because its getting used up by my corals? Would it drop by 0.5 every few days with a handful of SPS and several LPS corals, or is that big drop unless you have a fully stocked SPS tank?

Any ideas or suggestions for me at this point?
 
So I was talking with one of the guys from my favorite LFS and he thought I just have too many hard corals in my tank and really need to be dosing. I didn't think I had enough to have to worry about dosing, but when I go through the list I do in fact have quite a few. I went ahead and bought alk and calc to dose with but have only been doing the alk mainly because its an easy test for me to do and then I'll dose based on test results. I wish my calc test was easier - there are a billion steps in it! Anyhow, here's my list of hard corals - do you guys think its enough to explain where my alk is going?

Seven head trumpet (about to split into 10 heads)
2 two-head torches
2 large plates
2 small plates
large meat coral
australomussa
5 head frogspawn
1 head frogspawn
1 medium sized monti cap (good growth ring)
2 small monti cap frags (good growth rings)
1 small to medium monti cap
green birdsnest that grows like a weed
pink birdsnest that has only recently started to grow
5 polyp favia
acan enchinata
5 head acan
10 head acan
5 head duncan (recently went from 1 to 5 heads)
1 head duncan with 3 babies
large pearl bubble coral
blasto merletis (10 heads)
aussie blastos (4 heads)
8 chalice frags about 1-2 inches each
monti digi frag
pocillipora (3 inches across)
tricolor acro frag
ultimate blue stag frag
blue acro (2 inches across)
red acro (3 inches across)
strawberry fields acro
3 other SPS frags
sunset monti
3 superman montis
meteorshower
blue/green cyphastraea
2 sun corals

I think that's it.... I guess that is quite the list, huh? lol
 

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