Alkalinity of 5.3 dKH

[GoPitt88]

My 55 gallon mixed reef has been up and running for 20 months. I have 8 small fish and 12 different types of coral. (2 sps, 5 lps, 2 mushrooms, and a few leathers). I do weekly 10% water changes. Everything looks healthy, but since I've accumulated a bunch of coral, I thought I better check more than just nitrates and Phosphates, which both are normally zero. I bought Red Sea Reef Foundation Pro, and measured the following : calcium is 470, magnesium is 1530, but Alkalinity is only 5.3 dKH. My pH is 7.9 to 8.0. I also run a CO2 scrubber connected to my protein skimmer. Am I hurting my corals or fish with an Alkalinity of 5.3?

 

[Diesel]

Short answer YES.
5.3 ain't good for corals or the overall health of your system.
My question is how often did you test your ALK and is it possible that your test kit can be bad?
Reason I ask is that your PH is sitting close to normal with a low ALK reading this should be down as well.
How do you supplement the three.....ALK, CAL and MAG?
Most cases just water changes can't keep up with the parameters of the three in your tank, corals, coralline algae, skimmer etc are playing a factor in that.

 

[Crabs McJones]

You'll want to get your alk and ph up. Alk you want between 8 - 12 and PH you want around 8 - 8.5
What salt mix are you using? and are you dosing anything with your water changes?

 

[GoPitt88]

You'll want to get your alk and ph up. Alk you want between 8 - 12 and PH you want around 8 - 8.5
What salt mix are you using? and are you dosing anything with your water changes?

I'm using Instant Ocean Reef Crystals. I am not dosing anything. Just weekly water changes, religiously. This is the first time checking Alkalinity with new Red Reef test kit. I checked new batch of salt water before putting in tank, and the Alkalinity of that water was 11.2 dKH. I just ordered the BRS Bulk Kalkwasser Starter Package, so when I get it, I can start making slow adjustments.

 

[Crabs McJones]

I'm using Instant Ocean Reef Crystals. I am not dosing anything. Just weekly water changes, religiously. This is the first time checking Alkalinity with new Red Reef test kit. I checked new batch of salt water before putting in tank, and the Alkalinity of that water was 11.2 dKH. I just ordered the BRS Bulk Kalkwasser Starter Package, so when I get it, I can start making slow adjustments.

That's weird. Usually reef crystals is really good about having good levels. Are you doing 1/2 cup of salt to gallon of water? and how long has the bucket been sitting? I've been told that every once and a while you want to take your salt bucket and roll it around on its side a little bit to get everything mixed together again as it settles out over time.

 

[GoPitt88]

That's weird. Usually reef crystals is really good about having good levels. Are you doing 1/2 cup of salt to gallon of water? and how long has the bucket been sitting? I've been told that every once and a while you want to take your salt bucket and roll it around on its side a little bit to get everything mixed together again as it settles out over time.

Yes. My salinity is perfect. 1.025. I mix 2.5 cups with 5 gallons of water, and use a heater to match temperature of tank before doing water changes. Sometimes I let it sit overnight, but sometimes I only wait an hour or so after making a batch. Either way, I mix thoroughly before using.

 

[CodyRVA]

If your nutrients are very low or undetectable be careful, you don't want to raise your ALK beyond 8.5 dKH, in my opinion. As @Diesel mentioned, the short answer is yes, ALK that low is not good. Your PH is fine, mine rarely breaks 8.0. Validate your results with multiple kits before getting too drastic. Again as mentioned, it seems odd your ALK is that low and your PH is adequate.

In regards to ALK, what time of the day are you testing and are you testing multiple times a day?

 

[GoPitt88]

If your nutrients are very low or undetectable be careful, you don't want to raise your ALK beyond 8.5 dKH, in my opinion. As @Diesel mentioned, the short answer is yes, ALK that low is not good. Your PH is fine, mine rarely breaks 8.0. Validate your results with multiple kits before getting too drastic. Again as mentioned, it seems odd your ALK is that low and your PH is adequate.

In regards to ALK, what time of the day are you testing and are you testing multiple times a day?

I checked a couple times, once before the lights came on, and once about an hour after they came on. I will take your advice and try multiple kits, and test at different times of the day. Also at various times during the week between water changes. The last thing I want to do is anything drastic that will do more harm than good.

 

[GoPitt88]

Any recommendations for an alternate test for Alkalinity?

 

[GoPitt88]

I meant alternate test kit

 

[chipmunkofdoom2]

I'm using Instant Ocean Reef Crystals. I am not dosing anything. Just weekly water changes, religiously. This is the first time checking Alkalinity with new Red Reef test kit. I checked new batch of salt water before putting in tank, and the Alkalinity of that water was 11.2 dKH. I just ordered the BRS Bulk Kalkwasser Starter Package, so when I get it, I can start making slow adjustments.

Personally, I would not start with kalkwasser. Calcium hydroxide is a balanced additive, which means it boosts both calcium and carbonate alkalinity. Your calcium is fine, but your carbonate alkalinity is low. I would raise the alkalinity to a normal range before attempting to use a balanced additive like kalkwasser.

If you're looking for an alkalinity-only supplement, Randy Holmes-Farley wrote a great article on DIY two part solutions. You can make an alkalinity supplement using only baking soda.

As for an alkalinity test alternative, Salifert tests are pretty cheap and reliable.

 

[CodyRVA]

I checked a couple times, once before the lights came on, and once about an hour after they came on. I will take your advice and try multiple kits, and test at different times of the day. Also at various times during the week between water changes. The last thing I want to do is anything drastic that will do more harm than good.

If your coral look happy and healthy then you definitely want to confirm before messing with anything. If she aint broke don't fix her! +1 on Salifert kits, cheap and reliable. Alternatively, you could take a sample to various LFS's and see what kits they use or just some local reefers who might have different kits. If you're using API it's time to upgrade.

I also agree with @chipmunkofdoom2 your parameters seem pretty solid, don't get too excited. Try something simple to raise your ALK, assuming you have to, and then adjust accordingly. Take it slow, don't change to much too fast or you'll end up chasing your butt