2-part dosing confusion

[AquaJunkie]

So I'm supposed to be dosing in equal parts but my tank seems to be using a lot more alkilinity than calcium.

My tank is 100ltrs and I'm currently dosing 12mls of alkilinity and only 5mls of calcium per night which maintains my alk at 9dkh and cal at 450ppm and I'm using reeflowers 2-part supplements.

These levels seem perfect but I don't understand why I'm adding more alkilinity if corals use these supplements in equal parts.

I've noticed that coralline algae never seems to grow in my tank so something must be out of balance but I'm not sure what I can do to rectify it if my parameters are where they're supposed to be?

 

[Dr. Reef Verified Sponsor]

Alk at 9dkh and cal at 450 ppm is fine but depends what your mag levels are?
Also if you are running ultra low nutrient system then you need to bring your alk down to 7 dkh and cal around 420 ppm with mag 1250 to 1350. (ULN system are with nitrates and phos levels near or 0)
Once you have established where your system is then it's easier to know how much alk and cal you need to be dosing.
Normal consumption ratio is 2.8 dkh to 18-20 ppm of cal.
But in some tanks I have seen 3-4 dkh consumption per day.

 

[dode]

What's your magnesium at ? Cal mag & alk are all linked . If your mag is out , it could cause you problems with your other element's

 

[USMC 4 LIFE]

Coral from my research on this forum don't use it equally. Alkalinity is depleted more rapidly in a SPS tank as compared to a LPS or soft coral tank.

If you're maintaining levels by dosing 12 / 5 then you're doing just fine.

 

[AquaJunkie]

I test weekly and levels are always the same... alk 9kh- cal 450ppm and magnesium 1280ppm I'm tested using Red Sea pro tests

I'm running a mixed reef mainly sps and lps

 

[Dr. Reef Verified Sponsor]

It's quite normal for sps dominated or mixed reef to consume more alk.

 

[AquaJunkie]

So I shouldn't be worried at all then? I get zero coralline growth and my acros barely grow at all.

I have a load of montis and they do really well so I'm not sure what's going on at the moment.

 

[R_C]

Alk at 9dkh and cal at 450 ppm is fine but depends what your mag levels are?
Also if you are running ultra low nutrient system then you need to bring your alk down to 7 dkh and cal around 420 ppm with mag 1250 to 1350. (ULN system are with nitrates and phos levels near or 0)

Not to hijack this thread but can you please elaborate a little more on this? I have never heard of this and I'm thinking this is the reason my acros do not do very well in my tank.

Here are my levels:
Temp- 77
PH- 8.2
NH3- 0
NO2- 0
NO3- 1
PO4- 0
Salinity 1.025
Alk 9.8
Cal- 402
Mag- 1300

 

[Dr. Reef Verified Sponsor]

This has been discussed and i have read about it not sure the scientific reason behind it. ULN systems need to run alk much closer to NSW 7 dkh. Many hobbyists have reported alk burn on tips or not so good growth. Ill try to pull some articles on it if I can find somewhere.

 

[nervousmonkey]

Essentially, what's happening with higher alk and calcium levels, with little to no NO3 and PO4, is that the skeleton of the corals can be built rapidly, since it is made of alk and calcium (calcium carbonate), but the tissue of corals is made up of proteins, just like ours, which must have N and P to grow.
So what happens is what people call "alk burn", where you see white skeletal growth of the coral without tissue covering it. It looks like the coral was burned, but not really. It's just that skeletal structures can grow without the tissue.
That is why having low to zero NO3 and PO4 causes SPS, and esp. acros, to not do well.

 

[R_C]

Great info, Thanks! Will do more research on this.

 

[nervousmonkey]

Great info, Thanks! Will do more research on this.

It's really a pretty easy concept to grasp; frankly, once I realized that NO3 and PO4 were helpful and not necessarily bad, I stopped measuring them, keep my alk at 8.0 and calc at 425 (with doser), and I have never had better growth on all corals than I do now. I wasn't trying to get good growth, just health, but growth came along with that.