Water chemistry?

seecrabrun

Active Member
I've been working on turning my nano into a reef tank. Started back in January. The tank itself is 8 months old, so was 6 months when I decided to make the change.

I switched to Reef Crystals and researched test kits. Eventually I picked the Red Sea kits for calcium, alkalinity, and magnesium. I tested my water for the first time, and then probably a dozen more times the same day.

My values were high. Magnesium was 1600, Alkalinity was 11.5, Calcium was 565.(pH was 8.1, salinity 1.025) Of course I had nothing in the tank to make use of these.
Finally I tested the actual salt mix and it was even higher than these. Magnesium was 1660, Alkalinity was 14, and Calcium was 625.

After chatting with a few people, it was determined I must have had a bad batch of salt. So I ordered more. It came, I tested it. It was much closer to what the charts online said it should be for that brand. I didn't right it down, but I can test it again if it is important. The batch I had that we determined was bad was also VERY dusty, like make you sneeze- you can't escape- dusty. This batch is not like that. I can test it again if it is important though.

So that was 2-3 weeks ago or so. I've been using the new salt batch and tests have been good. Except my alkalinity. At first I thought it was because I started running some phosguard to try and combat the phosphate I was testing positive for. So I stopped using that. It's been over a week and my alkalinity is still now.

Today's tests, right before a 10% water change were as follows:

Salinity 1.025
pH 8.2
Ammonia and Nitrites 0
Nitrates 2
Phosphates .05
Magnesium 1400
Alkalinity 8
Calcium 440

I have 1 small 3 head duncan and 1 small acan, plus a coco worm. I've heard I need to stay on top of my alkalinity for the worm, which is why I'm so worried.

Could the worm be using so much of the nutrients? I do a weekly water change of 10% but I wouldn't think such a little thing could do it. It has been building its tube though, a lot faster than I expected to see it do so. I've had it 3 weeks today and 2 weeks today was the first sign of low alkalinity, but as I said I was also using the phosguard.

So I'm trying to learn and understand the water chemistry involved. I know pH, Magnesium, Alkalinity, and Calcium all go hand in hand with each other. Though I'm not sure how to determine if one is truly effecting the other.

I would really love to avoid dosing if possible. I'm up for doing more frequent changes if necessary. What I'd like to do is understand what causes the dips though, and address them if it is a problem.
 

bang guy

Moderator
Your Alkalinity is fine. The worm isn't going to need more, the Duncan and Acan would probably appreciate a slightly higher level though. Coralline algae could be consuming some at this point. If you see the Alkalinity drop below 6.5 dKH then do a water change or add a teaspoon of baking soda to each gallon of topoff water.
 

seecrabrun

Active Member
I'm going to test the water now that I've done the water change and see how much that brings it back up.

I'm concerned about being able to keep my levels at the right place with water changes alone. Would doing smaller and more frequent ones be better? I know a lot of people recommend doing small daily ones.
 

snakeblitz33

Well-Known Member
At 8dKH, I honestly don't see anything wrong. As long as it doesn't dip below 7. baking soda helps bring alkalinity up, but will slightly decrease pH. If your not having any pH issues, baking soda is great for keeping alkalinity up. If your pH is a little low, sodium carbonate works great - sal soda as it's called. You can buy it at pool supply shops.

Raising alkalinity more than 1dKH in one day can cause problems. Try to drip it in and avoid pouring it in where there is sand. It can cause clumping.
 

seecrabrun

Active Member
So after a 10% water change my pH is 8.1, magnesium 1480, alkalinity 8.4, and calcium 460.

So that raised the numbers slightly.
 
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