New tank...Alk keeps dropping...why?

timrocks311 · Apr 1, 2018

OK, I'm officially confused. I have a new 40 gal tank setup for about a month. Dry rock, dry sand. Cycled with Bio-spira about 1 week before adding anything. Only livestock are a 4 snails, 3 hermits, a hammer frag and a few zoa frags. I finally have diatoms as of today.

I'm confused with two things. 1. My hermits and snails barely move. 2. Despite dosing my Alk keeps dropping and I can't keep it above 8.

On #1, I thought it was lack of food, but I'm thinking it is something with parameters instead.

With the low Alk, I'm dosing BRS soda ash liquid. Using their calculator. My Alk was as low as 6.2 last week. On Wednesday Alk was 7.2, dosed 1.7 oz targeting 8.5. Tested Friday and it was only 7.5. On Friday I added another 1.5 oz, Saturday tested 8.3. Dosed another 1 oz trying to get to 9, and now today it is back down to 7.7.

I don't know why I can't get the Alk up. Test kit is a brand new salifert. Any thoughts? Other parameters are:

Temp 78-79
Salinity 1.025
Ammonia 0
Nitrite 0
Nitrate 15
Ph 8.2 (up from 8.0 all last week)
Calcium 425
Mag 1300
Don't have a phosphate test yet

Thanks!

timrocks311 · Apr 1, 2018

Also, I'll note, I'm using reef crystals. It is mixing up with an alk of 10. I noted my Alk dropped to 6.2 even before livestock. I dosed it up before adding any livestock. I'm just surprised by how much I'm dosing anand how much it is fluctuating. With the minimal stock I have I didn't think any parameters would be used up yet.

Maggie321 · Apr 2, 2018

Raise your mag. Higher mag can stabilize cal and alk I believe... also verify this before you do it.. lol

Maggie321 · Apr 2, 2018

timrocks311 said:
Also, I'll note, I'm using reef crystals. It is mixing up with an alk of 10. I noted my Alk dropped to 6.2 even before livestock. I dosed it up before adding any livestock. I'm just surprised by how much I'm dosing anand how much it is fluctuating. With the minimal stock I have I didn't think any parameters would be used up yet.

I am surprised RC your mag is that low... I use same and it runs about 1600 to 1700... strange, must be a different batch.

timrocks311 · Apr 2, 2018

I thought I was okay with Mag 1300-1350. What should I get it up to?

Maggie321 · Apr 2, 2018

Technically 1300 is good. At a bit higher number, it should stabilize. Your other parameters are likely precipitating out. Ant in reality, since you don't have much for corals yet, I would not be doseing if I were you. A 10 to 20% water change weekly should be fine.

Randy Holmes-Farley · Apr 2, 2018

I don't really see anything unusual or unexpected. The alkalinity drop is fairly small, 0.5-1 dKH per day, and it will be larger as you boost the alk higher. It is probably mostly abiotic preciptiation of calcium carbonate, plus some small amount of consumption. There is always abiotic precipitation, and more in new tanks that have lots of raw calcium carbonate surfaces for precipitation to happen.

I'd let the alk drop to 7 dKH and maintain it there, and switch to baking soda for any needed dosing (keeping the pH lower and so precipitation lower).

You will probably need to start dosing calcium before long too.

timrocks311 · Apr 2, 2018

Randy Holmes-Farley said:
I don't really see anything unusual or unexpected. The alkalinity drop is fairly small, 0.5-1 dKH per day, and it will be larger as you boost the alk higher. It is probably mostly abiotic preciptiation of calcium carbonate, plus some small amount of consumption. There is always abiotic precipitation, and more in new tanks that have lots of raw calcium carbonate surfaces for precipitation to happen.

I'd let the alk drop to 7 dKH and maintain it there, and switch to baking soda for any needed dosing (keeping the pH lower and so precipitation lower).

You will probably need to start dosing calcium before long too.

Thanks for the input. I was targeting maintaining alk between 8-9 and thought a higher pH around 8.2 would be better. I've been pretty regularly at 8.0 with pH. Will a lower alk closer to 7 have negative effects?

I guess it is best to maintain it there until I have more consumption from more corals. It would keep me from dosing unnecessarily. My hammer looks very nice and happy btw.

Randy Holmes-Farley · Apr 2, 2018

timrocks311 said:
Thanks for the input. I was targeting maintaining alk between 8-9 and thought a higher pH around 8.2 would be better. I've been pretty regularly at 8.0 with pH. Will a lower alk closer to 7 have negative effects?

I guess it is best to maintain it there until I have more consumption from more corals. It would keep me from dosing unnecessarily. My hammer looks very nice and happy btw.

Higher pH is "better" if coral growth is the goal. It is worse if abiotic preciptiation is a problem. It is a huge driver of precipitation.

7 dKH is actually a bit above the natural value in the ocean. It's hard to believe it could be characterized as "negative" effects.

Once you calcium carbonate surfaces get more covered in things like organics, bacteria, phosphate, magnesium, etc., then precipitation is typically less.

timrocks311 · Apr 2, 2018

ok, thanks again.

Flexin · Apr 2, 2018

I would consider giving your tank time to age and mature before chasing parameters. How often do you perform water changes and how much water each change (as part of your ongoing routine)?

timrocks311 · Apr 2, 2018

Flexin said:
I would consider giving your tank time to age and mature before chasing parameters. How often do you perform water changes and how much water each change (as part of your ongoing routine)?

I performed a 5 gallon change when adding my first livestock. I was going to target 5 gallon changes every 2-4 weeks. It's early still so I wasn't concerned with doing a ton of water changes. I was targeting good parameters thinking they would hold steady with minimal consumption from livestock at this point, and I wouldn't have to dose for a while.

nhlives · Apr 2, 2018

My early tank experience is that you tend to overdose ALK.

timrocks311 · Apr 2, 2018

nhlives said:
My early tank experience is that you tend to overdose ALK.

I realize that now and I'll stop. Thanks.

Randy Holmes-Farley · Apr 2, 2018

timrocks311 said:
ok, thanks again.

You're welcome.

Happy Reefing.

Ferrell · Apr 4, 2018

I too had the same problem in the first few months of mine. As to slowly get life and critters in there all will slowly stabilize. I know where you’re coming from and I had to keep telling myself to relax and go slow. It paid off so far.
Good luck and happy reefing

timrocks311 · Apr 4, 2018

Ferrell said:
I too had the same problem in the first few months of mine. As to slowly get life and critters in there all will slowly stabilize. I know where you’re coming from and I had to keep telling myself to relax and go slow. It paid off so far.
Good luck and happy reefing

thanks for the comment. good to hear it's normal.

DOJOLOACH · Oct 7, 2020

Randy Holmes-Farley said:
Higher pH is "better" if coral growth is the goal. It is worse if abiotic preciptiation is a problem. It is a huge driver of precipitation.

7 dKH is actually a bit above the natural value in the ocean. It's hard to believe it could be characterized as "negative" effects.

Once you calcium carbonate surfaces get more covered in things like organics, bacteria, phosphate, magnesium, etc., then precipitation is typically less.

Randy,
I added my first and only stony lps corals to my tank 4 days ago, 2 small favia frags. It has been 4 days and my alkalinity dropped .7 dkh in a 50 gallon tank. Does this sound odd? I wouldn't think the coral frags would start off that well absorbing dkh. Calcium level seemed to stay the same