Alkalinity advice

[MrObscura]

Just looking for some advice on how to handle this crucial parameter. My nuvo 10 has been set up for a few months now and currently has 7 stony frags and some zoas and shrooms. I use red sea coral pro salt and at. 025 it mixes to around 11-11.5dkh.

 

My tanks alk is the nines now. I do a 20-25% water change per week, so I was wondering how I should proceed? Should I start trying to bring it up to rscp levels or just stick to water changes for now? Thanks. 

[medinar83]

I'm kinda on the same boat w/ my 13.5 

[MrObscura]

Hopefully someone will chime in. 

 

[vegasgundog]

9s really not that low. Bottom end. Stability the key. Until your stoney corals or coraline algae groing, water changes will probably suffice. Check weekly if you do weekly wc.

[MrObscura]

Yea, I was just wondering if I should start bringing it up to rscp levels now or leave it be fow now as long as it's stable. 

 

Which brings me to another question. Are Alk levels directly proportional to wc amount? For example, will a tank with 9dkh end up with 10dkh if a 50%wc is done with water at 11dkh? Or are the changes more subtle? 

[vegasgundog]

I believe it's more subtle. I was dosing 35ml every day before I broke down the red sea. Now that I'm up to 120gal, I'll be dosing until I'm up to 10. After set up it was only 8.4, guess I should have checked the level of the 80 gallons I made for the setup. I know from my experience my acans like at least 9dkh but 10 gives more room for slight swings. I will be running a doser once it starts dropping noticable amounts.

[MrObscura]

Once my tank is fully stocked it'll be mostly LPS and sps so I'll need to dose at some point. The final vision more sps than anything. More montis than anything else. I really dig montis. so I guess sps dominate technically, but more proportional, so a mixed reef really.

 

When that times comes I'll slowly bring Alk up to the level of my mix water. But if 20-25% WC won't alter things much I'll just stick with water changes until things start dropping to much. 

[Clown79]

9 is perfectly fine. 7-10 is normal.

 

Stability is the key.

 

What I'm curious about is If your salt is mixing at 11 how come the tank is 9?

 

Is 9dkh after a waterchange or after a few days of consumption

 

Have you tested your tank after a waterchange to see where the alk begins at? 

 

 

[MrObscura]

I've been testing both right before and after waterchanges. For a little while it stay around 11-11.5 or so. Then in the 10s and now the 9s. I guess my tank has simply starting consuming Alk quicker than I thought it would with just frags. And I guess it's just in the 9s now because the partial wc isn't enough to raise it much. 

 

But I didn't test this week right after the wc because I was waiting for my hannah checker to arrive. I had been using red seas Alk test but I don't trust my reading completely since I have trouble with knowing exactly when it changed color and reading exactly how much liquid is left in the syringe. 

 

I do my next wc Friday so I'll test before and after.  I was just concerned with how much a 25% WC could alter Alk. 

[ReefGoat]

http://reefkeeping.com/issues/2004-12/rhf/index.htm    I like this article on all things alkalinity and calcium. I believe it was penned by the man himself. Randy Farley. It may or may not help you. But it's still a must read in my opinion. 

[MrObscura]

48 minutes ago, ReefGoat said:

http://reefkeeping.com/issues/2004-12/rhf/index.htm    I like this article on all things alkalinity and calcium. I believe it was penned by the man himself. Randy Farley. It may or may not help you. But it's still a must read in my opinion. 

While some of it was admittedly hard to wrap my head around, it was informative. And though it didn't solve how I should approach my tank going forward it did give me a answer as to how water changes alter Alk. Converting meq/l to dkh, according to the article a tank with 11.2dkh given a 20% WC with 7dkh water will result in a final Alk reading of 10.2 or so. So it is pretty much directly related to dkh vs volume. I'm assuming it works the opposite way as well if you add higher Alk water to lower levels. 

 

That said, unless you're doing a 30%+ wc with water 4 points or more off it shouldn't have any short term effects. 

[Clown79]

1 hour ago, MrObscura said:

While some of it was admittedly hard to wrap my head around, it was informative. And though it didn't solve how I should approach my tank going forward it did give me a answer as to how water changes alter Alk. Converting meq/l to dkh, according to the article a tank with 11.2dkh given a 20% WC with 7dkh water will result in a final Alk reading of 10.2 or so. So it is pretty much directly related to dkh vs volume. I'm assuming it works the opposite way as well if you add higher Alk water to lower levels. 

 

That said, unless you're doing a 30%+ wc with water 4 points or more off it shouldn't have any short term effects. 

The easiest way to know what is going on

 

Is test new mixed water

 

Test tank after waterchange

Test every day until the next waterchange

 

This will show you what you are starting at and how much the tank consumes.

 

 

And yes, if you allow the tanks levels to drop from 11dkh, when you do a waterchange it will alter the tanks levels.

 

The only way to know how much your tank is dropping is by testing

 

 

[Ebn]

I prefer to match alkalinity to nutrient levels. My tank is pretty low in nutrients so I run it in the 7.7 - 8.0 range. I've been as low as the 6.7 range as well while dialing in the calcium reactor. Acans and acros don't mind as long as the change is gradual and subtle. I use IO salt and the current batch settles in at ~8.8 within 24 hours (initial mix is in the 11-12 dKH range). 

[Clown79]

30 minutes ago, Ebn said:

I prefer to match alkalinity to nutrient levels. My tank is pretty low in nutrients so I run it in the 7.7 - 8.0 range. I've been as low as the 6.7 range as well while dialing in the calcium reactor. Acans and acros don't mind as long as the change is gradual and subtle. I use IO salt and the current batch settles in at ~8.8 within 24 hours (initial mix is in the 11-12 dKH range). 

Very good point.

 

Low nutrients and high alk can be an issue.

 

I learned that the hard way when I switched to rscp

[MrObscura]

I've heard that about low nutrients and high Alk, but interestingly when I asked bulk reef supply about that they said it's not an issue. 

 

Eitherway running higher alk shouldn't be an issue since I usually seem to have nitrates around 5-10.

 

Id like to keep the tank at the same levels rscp mixes to to avoid any issues, but I didn't think it'd drop so soon or so quick. How should I go about raising the Alk in the tank safely? Just use a little bit of kalk at a time, or dose slightly, until it's there? 

 

For starters though I'll definitely get a reading directly after tomorrow's wc and then another 24 hours later so I have a baseline. 

[Ebn]

I asked them about the nutrient levels in their test tanks recently since they did an elevated experiment video. FYI, they only track nutrient input and don't measure accumulation so you won't find that info from them. It's interesting because in that video you can see obvious signs of algae on the elevated tank but not in the control or the normal level tanks, which could be attributed to higher levels of nutrients. They say it's not an issue because they failed to measure it in their experiment versus actually doing so. 

 

You can use either kalk, sodium carbonate, or sodium bicarbonate to bring your alk up. I use sodium bicarbonate since I have leftover solution mixed from BRS bulk. If you plan on raising it, then don't do it too quickly (no more than 0.5 dKH/day). 

[Clown79]

18 minutes ago, MrObscura said:

I've heard that about low nutrients and high Alk, but interestingly when I asked bulk reef supply about that they said it's not an issue. 

 

Eitherway running higher alk shouldn't be an issue since I usually seem to have nitrates around 5-10.

 

Id like to keep the tank at the same levels rscp mixes to to avoid any issues, but I didn't think it'd drop so soon or so quick. How should I go about raising the Alk in the tank safely? Just use a little bit of kalk at a time, or dose slightly, until it's there? 

 

For starters though I'll definitely get a reading directly after tomorrow's wc and then another 24 hours later so I have a baseline. 

First start with the testing part. You can't safely dose without knowing what is happening on a daily basis with your alk

[MrObscura]

Well I did a WC today and before it Alk was 9.1, and mix water was 11. And somehow after a 20% WC the tanks at 10.2

 

I figured it would only change by half a point or so. Can testing right after the wc effect the reading? 

[Clown79]

Sounds about right with the levels. 

[MrObscura]

I'm going to test every day for the week to see what the tanks consuming.  Then slowly bring it up to the mix water levels and keep it there. 

 

 

[MrObscura]

Just came across something interesting. Apperantly Jason fox pays little attention to Alk.  Even says his tanks can see a swing of 2 or 3dkh a day. 

 

Now im not saying we should all forget about it. Keeping things stable seems like best practice. But as usual the reality is probably in the middle, whereas some claim anything more than a. 5 swing is the end of the world and others don't worry about it at all, truth is corals can  probably handle a 1-2dkh swing just fine as long as Alk remains in a safe range and they are healthy to begin with. This is just a noob opinion of course. 

[Clown79]

8 hours ago, MrObscura said:

Just came across something interesting. Apperantly Jason fox pays little attention to Alk.  Even says his tanks can see a swing of 2 or 3dkh a day. 

 

Now im not saying we should all forget about it. Keeping things stable seems like best practice. But as usual the reality is probably in the middle, whereas some claim anything more than a. 5 swing is the end of the world and others don't worry about it at all, truth is corals can  probably handle a 1-2dkh swing just fine as long as Alk remains in a safe range and they are healthy to begin with. This is just a noob opinion of course. 

From my personal experience, when fluctuations have occurred more than 1dkh a day and I wasn't dosing properly to maintain it, I saw the effects of it on my stony corals.

 

Otherwise I don't dose if it's not significant amounts of daily consumption

[MrObscura]

Just tested Alk after 24 hours and it's dropped about .5. 

 

Is that a normal drop for 24 hours with just some stony frags? Granted it is a 10 gallon. 

[Clown79]

There really is no definitive amount a tank consumes.

 

Each tanks different due to livestock and also growth rate of corals.

 

 

[Sjadet]

5 hours ago, MrObscura said:

Just tested Alk after 24 hours and it's dropped about .5. 

 

Is that a normal drop for 24 hours with just some stony frags? Granted it is a 10 gallon. 

Seems reasonable. I have a 12g heavy stocked sps tank (12.5dkh) that drops 3dkh a day although dosing 0.5dkh every 4 hours.

In my experience consumption slows down as the alk levels drop. I did an experiment and my alk actually never goes below 6dKh, that said it also halts all coral growth.