Alkalinity range and too low

[ekean45]

I've been trying to research Alkalinity and it looks like there are some pretty big differences of opinion.

In mid September, I began using the Red Sea line of products - Reef Foundation, Reef Energy, and Coral Colors. Corals have become much more vibrant except I had a Candy Cane die and a Duncan that is not doing too well. I had added them into the tank about a month after starting the Red Sea products.

Other corals like monti's, hammer, frog spawn, leather, stunner chalice, mushrooms, war coral, and zoa's are doing great.

Since I started using Red Sea, my tank metrics have stabilized with the exception of Alk - started at about 8 and is now down to about 6.

What is considered a good range for Alk in a reef tank? If 6 is too low, how can I raise Alk without causing the other metrics to go out of whack.

Here's the current set-up and metrics:

• 65 gallon DT
• 10 gallon refugium
• Make my own RO/DI water
  • 10% water changes weekly
  • Lighting (I know not the greatest but it is what it is)Current Orbit Pro Marine (48")
  • ATI T5 Blue Plus
  • ATI T5 Purple Plus
    
  Dose 15ML AcroPower weekly

• I've been using a doser so additives are dosed daily. Only exception is the Red Sea Magnesium (Foundation C). For that, I am adding on a weekly basis.

• Salinity - 1.026
• Temp range - 79-82
• PH - 8.3
• Calcium - 450
• Magnesium - 1400
• Phosphate, Ammonia, Nitrite - 0
• Nitrate - 2
• Alkalinity is currently at 6 - Since I switched to Red Sea, I have been testing weekly so here is the downward progression. I had thought maybe the Alk test kit was bad (also Red Sea) so last week, I ordered a new one - also Red Sea.
  • 9
  • 9
  • 9
  • 10
  • 8
  • 8
  • 8
  • 8
  • 7
  • 7
  • 7
  • 8
  • 7
  • 8
  • 6

Any advice?
Could the downward trend have contributed to the Duncan/Candy Cane issues?

Thanks!

 

[TheEngineer]

What's strange to me is that your alk is dropping, but your calcium isn't. My guess is that what you are dosing is not balanced. For example, a lot of people dose two part. You dose it in equal amounts and it maintains the proper ratio of alk, calc and mag. Thinking more about your dosing, was something not maintained by your regular water changes which brought you to start dosing? Typically alk, calc, mag are well maintained just by water changes.

Your alk is definitely low, but not dangerously so IMO. You'd like to be above 7 dKH. I strive for around 9 dKH. You could start by looking at what the items you are adding to your tank actually provide. You might find none provide alk.

 

[ekean45]

I went to dosing because it appeared that the coral was just not looking healthy and did not have that "pop" you see. I fugured using a doser would be much more accurate in dosage as well as being done the same time daily. The dose concerning the ratio's are all done per the instructions on the Red Sea instructions. My goal was to have Alk at 8 dKH so dropping to 6 has gotten me concerned. What Alk level would be considered dangerous?

Reef Foundation B, which I am dosing, is the supplement that buffers Alk. I had re-calibrated the doser about a month ago but maybe I'll recheck to make sure it's working correctly. I am also going to change the salt mix I am using to one that might be better.

Thanks for your feedback.

 

[nervousmonkey]

Do you have higher levels of nitrates before your water changes? If so, you are taking out one of the ways that a tank reclaims alkalinity. If that doesn't happen, like with most of our tanks nitrate removal systems to keep nitrates so low (unless you are trying to run close to an ULNS, I'd let that NO3 rise a bit since you are not keeping SPS. Those critters you have like a bit higher nitrate level in the water, or "dirty water". Either way, you are physically removing alkalinity with every WC by taking nitrates out that have not released their alk. Randy H. has some great equations about it here:
https://www.reef2reef.com/threads/nitrates-down-through-water-changes.245269/

Either way, you should have at least an 8, but maybe higher, as in 8.5, but not higher. Your level of nitrate will only support a range that's low, but not as low as 6. That's what is causing your Duncan/Candy Cane, so you are correct, the issue of low alk in the downward trend caused your Duncan/Candy Cane issues.

Test the pH of the Red Sea when you mix a fresh batch, and then keep your alk, calc and mag the same as what is in the bag (you can make them higher but it's a pain to keep doing), and everything will be fine. Get your pH up and it'll fix the issue.

BTW, alk is one of the parameters that drops as nitrates get removed, so calc and mag would still look good. Sometimes you just have to dose extra alk, or alk increasing products...

 

[ahammer]

I believe an alk of 6 is harming the coral. As you add coral you must increase the alk dosage typically. What I believe to be happening, as I use the same program, is that you are not dosing enough reef foundation b. Your calcium probably gets a nice boost from the water changes while alk is minutely affected. I know Red Sea prefers a 12 alk, but I have great success at 9.

 

[ekean45]

My nitrate level before the water change is usually between 0-2 - does not usually going any higher. That's before I started the Red Sea program. That's really interesting - You are taught to have lowest nitrates as possible and that water changes are paramount to maintaining a healthy reef tank. I have a "show" refugium (long story but it is a separate 10 gallon tank next to the DT), with several types of macro algae that is thriving. Have to cut back some of it every few days. I thought that macro's help to absorb nitrates and provide a good exchange for the reef/fish. Could this actually be affecting the Alk because it takes the nitrates out?

 

[ekean45]

I believe an alk of 6 is harming the coral. As you add coral you must increase the alk dosage typically. What I believe to be happening, as I use the same program, is that you are not dosing enough reef foundation b. Your calcium probably gets a nice boost from the water changes while alk is minutely affected. I know Red Sea prefers a 12 alk, but I have great success at 9.

Last night, I increased the dose of Reef foundation B so I'll see what happens over the next few weeks. Hopefully next week, it will have either stabilized or slightly increased.

 

[ekean45]

Do you have higher levels of nitrates before your water changes? If so, you are taking out one of the ways that a tank reclaims alkalinity. If that doesn't happen, like with most of our tanks nitrate removal systems to keep nitrates so low (unless you are trying to run close to an ULNS, I'd let that NO3 rise a bit since you are not keeping SPS.

nervousmonkey - this might sound redundant but based on what you are saying, do you think I should space out the water changes to every 2 weeks instead of weekly? If so, I will plan to do so after I see the results of dosing Reef Foundation a bit higher if that does not solve the problem. I'd like to see what the cause of the problem is and not try 5 different things at once.

Also - And if you think I should space out the water changes and it still does not solve the issue, would you suggest cutting back on the amount of macro algae in the refugium?

 

[twilliard]

From what I see you are not dosing enough Alk, bottom line.

 

[ekean45]

From what I see you are not dosing enough Alk, bottom line.

I hope that is the root problem but from I am reading, there are other things that can cause Alk to drop and many times trying to correct one throws other metrics out of balance. I was not really all that concerned until the level dropped as low as it is now. I was really hoping it was the test kit giving bad readings, but the new one I got is giving me the same results.

 

[Randy Holmes-Farley Verified Community Expert]

I hope that is the root problem but from I am reading, there are other things that can cause Alk to drop and many times trying to correct one throws other metrics out of balance. I was not really all that concerned until the level dropped as low as it is now. I was really hoping it was the test kit giving bad readings, but the new one I got is giving me the same results.

It's really not that complicated. Assuming the 6 dKH is accurate, dose more. Dose equally more calcium too, if you are using a two part, unless calcium is already too high.

 

[ekean45]

It's really not that complicated. Assuming the 6 dKH is accurate, dose more. Dose equally more calcium too, if you are using a two part, unless calcium is already too high.

It is 2 part. Alk is in Reef Foundation B and calcium is in Reef Foundation A. Calcium is currently at 450. If I dose additional calcium to correct the Alk, wouldn't that raise calcium too high?

 

[twilliard]

You dont want to dose more calcium

 

[twilliard]

Just dose ALK for correction

 

[ekean45]

Just dose ALK for correction

Thanks!

 

[nervousmonkey]

nervousmonkey - this might sound redundant but based on what you are saying, do you think I should space out the water changes to every 2 weeks instead of weekly? If so, I will plan to do so after I see the results of dosing Reef Foundation a bit higher if that does not solve the problem. I'd like to see what the cause of the problem is and not try 5 different things at once.

Also - And if you think I should space out the water changes and it still does not solve the issue, would you suggest cutting back on the amount of macro algae in the refugium?

You can try this, or if your tank is healthy, do as @twilliard said and just dose more alkalinity, bring your pH up to the levels you want, observe and make sure this is helping. I think this is the major problem here, and raising alk will fix the problems. You have a great pH, coming from your macros consuming the CO2 in your tank, so just keep doing what you are doing with the macros. Don't change that at all, they are keeping your tank with great parameters.
I was just saying that sometimes alkalinity can be removed by water changes and some other factors (minimal though), and that it needs to be dosed a little more than the recipes state, or in your case, Red Sea. Alk can be taken up by things that calcium can't, so your other parameters can be inline and your alk out of whack.

Just dose more alk, or Red Sea part 2, and you'll be fine with no other changes made to your tank. FWIW, I use the Red Sea program as well with two part like you, and always need to dose more alkalinity. That's in addition to having kalkwasser in my ATO. I haven't figured out why my tank drops alk, but it does, so I just dose more to keep in line with everything else....

 

[nervousmonkey]

Additionally, since the subject of NO3 in our tanks came up (in respect to reducing alk through WC's), I'm glad @twilliard responded. He knows a ton about the levels of NO3 we need in our tank. That's a separate thread though. just stick to the alkalinity for now.

 

[ekean45]

Awesome feedback - thanks a ton. Can't imagine how much more difficult this would be before the Internet!

 

[twilliard]

Awesome feedback - thanks a ton. Can't imagine how much more difficult this would be before the Internet!

A lot of trial and error

 

[nervousmonkey]

Awesome feedback - thanks a ton. Can't imagine how much more difficult this would be before the Internet!

I know. Much harder when it was just a LFS, but we didn't keep the corals we kept now back in those days. Having this forum with people with Ph.D's in the forums repsonding to questions, like Dr. Randy, and Todd W., who has dedicated a lot of learning about all kinds of things in our reef tanks, responding and keeping it simple, makes a huge difference.