What KH level am I shooting for with my reef?

[AlmightyJoshaeus]

Hello all! My 10 gallon macroalgae/reef hybrid tank I am setting up for my mum and that has run since about the middle of October is still doing very well...today when I did a water change, I found no nitrate or phosphate in the tank before the 20% water change (I did not test calcium, but last time I tested it it was 540 ppm and there is only a small patch of halimeda that would be reducing it...probably still quite high). However, the KH came out as only 6 degrees...is this too low for a good reef? I am expecting a purple blade gorgonian frag in the mail late this month or perhaps early next month. (For those concerned, this tank has a 14000k LED light meant for a reef and has a turnover rate of 30 times an hour).

[RIP Sebastian]

Hello all! My 10 gallon macroalgae/reef hybrid tank I am setting up for my mum and that has run since about the middle of October is still doing very well...today when I did a water change, I found no nitrate or phosphate in the tank before the 20% water change (I did not test calcium, but last time I tested it it was 540 ppm and there is only a small patch of halimeda that would be reducing it...probably still quite high). However, the KH came out as only 6 degrees...is this too low for a good reef? I am expecting a purple blade gorgonian frag in the mail late this month or perhaps early next month. (For those concerned, this tank has a 14000k LED light meant for a reef and has a turnover rate of 30 times an hour).

Since your tank has no stony corals in it, I wouldn't worry about it.

[AlmightyJoshaeus]

So that's fine for stuff that's not LPS or SPS corals?

[RIP Sebastian]

So that's fine for stuff that's not LPS or SPS corals?

Yes. It is used by stony corals to build skeletons. If you don't have any stony corals, don't worry about it.

[Clown79]

Alk should be 7 or more. Not just stony coral rely on alk. Alk is very important in a reef tank.

 

Alk also effects your ph so its important for alk to be in normal ranges or you will have ph issues.

 

Your ca is probably high because the alk is low. Its not balanced. As alk drops ca increases.

 

http://www.advancedaquarist.com/2002/2/chemistry

 

This explains the importance of alk and what it effects.

[AlmightyJoshaeus]

So...what can I do to fix that? I'm using the instant ocean reef crystals...I didn't expect this to be a problem (there's very few things in this tank that would be making a calcium skeleton...do carbonates get devoured in photosynthesis by macroalgae like what some hardwater aquarium plants do?)

[Clown79]

I use to use reef crystals and my alk was at 7. My ca was 400, my mag was 1050-1140.

 

I had only softies. My ca and alk would drop in 4 days.

 

Hermits, snails, etc all use alk.

 

Lps and sps use more but out of personal experience, i had params drop with only softies.

[Clown79]

How old is the tank?

 

Now is it your newly mixed water that the you are getting these readings or your dt?

 

What does you newly mixed water parameters test at?

 

You could dose. I had to start dosing after 5mnths.

 

Before dosing i would check magnesium. If magnesium is low, ca and alk won't balance and that could be the issue.

 

I would determine if its usage of tank or if the mixed water is coming out low

[markalot]

I suspect a testing error.

 

WHat test kit do you use?

 

You say degrees ... do you mean dKH? Carbonate Hardness.

[AlmightyJoshaeus]

Yes, dKH. Got the 6 dKH reading from the old water. This is a macroalgae tank with caulerpa, chaeto, halimeda, a couple others...but no animals as of yet. Adding the new water brought the tank back to 7 degrees, but I opted to add an eighth of a teaspoon baking soda just in case, which pushed it up another degree. Infuriatingly, I have no magnesium test kit...it didn't come with the API test kit I have been using. Will need to get one.

 

Have had the tank running since the middle of october, feeding flakes daily or semi daily. Ammonia, nitrate, phosphate, and presumably nitrite were all zero even before the water change.

[Clown79]

When you mix your water for waterchange, test that water for ca, alk, and mag.

 

Then test your tanks water after waterchange.

Test the next day.

 

This is the only way to determine if its the water/salt mixing at low levels or if your tank is consuming alk.

 

Api has no mag test kit.

 

Don't dose willy nilly. Your tank is 2 mnths old. Dosing blindly can lead to problems.

 

You need to determine if its the waterchange water or usage of tank. Once you know the answer then go from there.

 

If indeed your tank is consuming alk, knowing how much its consuming is important so that you can dose accordingly. (The testing schedule above will help figure it out)

 

2 part dosers are better to use. It keeps your alk and ca balanced.

[AlmightyJoshaeus]

Pity...off to look for one from another brand. What can I add to increase calcium or magnesium, if needed? (Not likely to need to dose calcium for a while, but just in case...) My idea for KH was to test the tank's new KH after each water change and, if the value was below a certain point (perhaps nine degrees?) add small quantities of baking soda until it hits 9 degrees. Of course, before that I will test to make sure this is not a fluke stemming from poor salt mixing. Thankx

[Clown79]

I'd start by stirring up your salt. If its in a bucket, roll the bucket.

 

Then i'd test your newly mixed water. See what the levels come out at.

 

What salt are you using and at what salinity? This is important info. Salt mixed at different salinity levels gets different results.

 

If its your salt, everytime you do a waterchange, your water will be different than the tanks water, if you dose the tank, which will cause issues.

 

Example. You dose your tank to get it to 8dkh but your water mixes at 6 dkh. When you do a water change, it will cause a big fluctuation. I had that with my magnesium. I'd dose and get it to 1250 but do a water change and it would drop to 1140. Thats because my salt mixed at 1140.

 

Some may dose their newly mixed water, i've read somewhere ppl doing that but the better option is using a different salt with numbers you want and dosing the tank when it uses up the elements.

 

Its essential to know how much the tank uses to dose properly or else you may over dose or have fluctuations which leads to bigger issues.

 

Your tank doesn't have anything in it to use up these elements besides rock and one coral. It won't use that much. So testing your mixed water is where you start.

 

I only dose because my tank uses up alk, ca, and mag daily but my water mixes to what i want so i keep the tank stable by dosing..

 

As for poor salt mixing. Each salt is different so the procedure may be different.

 

With my reef crystals i stirred my salt, then slowly added it to water while stirring it. Checked salinity. Once correct, i added my heated and powerhead, mixed for 4 hrs then did waterchange.

 

With instant ocean i did the same thing but mixed it 24hrs.

 

Red sea coral pro. I stir my salt, add slowly while stirring, check salinity. After 2 hrs i add my powerhead and heater. I don't mix it for no more than 4hrs. Thats the instructions.

[AlmightyJoshaeus]

Haven't finished getting new water for this week yet, but the KH in the 10 gallon has dropped from 8 to 7 degrees...suffice to say it's getting consumed by something (and calcium is still 540 ppm, so it's not the halimeda...some quick research confirms that macroalgaes can use carbonates and bicarbonates in photosynthesis, so I am pretty sure that's what happenning).

[markalot]

Halimedia (I can't spell it) uses calcium and probably Alk as well, coraline algae uses Alk. Stop testing calcium unless you dose it separately (not as part of a balanced dosing system). The calcium scale is different and a drop of 2 KH will barely move the calcium number. Do you know the relationship? Stop guessing, look it up.

 

If you are really worried about keeping params stable then buy a two part system and dose equal parts (per bottle instructions) from time to time to keep Alk steady. You can get a DIY two part mix from Bulk Reef Supply or just buy pre-mixed. I use C-Balance when I need to dose but Kalk is my main way of keeping params stable.

 

Rather than be concerned with what is using Alk you should make sure testing is accurate and find a balanced way to maintain params. In my opinion regular small water changes with a high KH salt like Reef Crystals or Red Sea Coral Pro should take care of things. Since you don;t have stonies you can swing Alk up and down, within reason.

 

I literally test Calcium twice a year, maybe 3 times if I'm really bored. Alk is the most important param and as long as you are providing Alk as part of balanced dosing system Calcium will settle into a natural range and stay there. Magnesium is slowly depleted but typically water changes are enough to replenish it.