Dkh at 12 or 8 for sps

[tling]

Hi senior,

My red sea buffer power supplement recommend sps to have 12 dkh and lps at 8.1 dkh. My current dkh is around 10.5 already using DD test kit. Should I bring it up higher?

[LittleBurger]

Hi senior,

My red sea buffer power supplement recommend sps to have 12 dkh and lps at 8.1 dkh. My current dkh is around 10.5 already using DD test kit. Should I bring it up higher?

Most of time I read the web, 10 is the magic no for sps. maybe u wan to Google more to confirm.

[ShadowHunter]

I used to get 8-9 but after dosing Seachem Reef Builder, kH can maintain at 12-13. You will see better coloration.

[honkit]

The most important thing to remember for kh values is to keep it at a stable level with minimal fluctuations. Naturally, this value will be where your sps corals are comfortable with.

For ULNS tanks with bacterial systems, keep dkh values below 8 to avoid burnt coral tips.

[klim]

May I know what is ULNS? Thanks

[netviper]

Should be ultra low nutrient system.

Btw, bro honkit, wats ya dkh level?

[honkit]

Yes, it is an acronym for ultra low nutrient system.

I keep my tank's level at 7.5.

[jquek]

The most important thing to remember for kh values is to keep it at a stable level with minimal fluctuations. Naturally, this value will be where your sps corals are comfortable with.

For ULNS tanks with bacterial systems, keep dkh values below 8 to avoid burnt coral tips.

Hi bro, can you elaborate a little further on keeping dkh below 8 for ULNS? I read that too from many forums but no one seem to say why. Anyway, I suspect some of my spses are not doing well because of this though I am not sure. My current dkh is around 9.2 - 9.5 and some of my spses start to stn from the tips even though they seem to be doing ok initially for weeks. I run bio pellets (dosing prodibio biodigest weekly) and rowaphos in FRs and my NO3 and PO4 are both about 0.25 (DD test kit) and 0 (Hanna checker) respectively. Thanks in advance for any advice.

[honkit]

Hi bro, can you elaborate a little further on keeping dkh below 8 for ULNS? I read that too from many forums but no one seem to say why. Anyway, I suspect some of my spses are not doing well because of this though I am not sure. My current dkh is around 9.2 - 9.5 and some of my spses start to stn from the tips even though they seem to be doing ok initially for weeks. I run bio pellets (dosing prodibio biodigest weekly) and rowaphos in FRs and my NO3 and PO4 are both about 0.25 (DD test kit) and 0 (Hanna checker) respectively. Thanks in advance for any advice.

My definition of ULNS is a reading of 0.03 or less using a phosphate Hanna checker. Nowadays, I use visual cues such as signs of SPS tissue darkening and the rate of algae growth on my tank walls to watch for any elevations of PO4 levels.

There is no hard evidence that explains why such sps coral tips are stripped of tissue when dkh levels are above 8.0 in a very low nutrient tank but they do happen often enough based on my and others' anecdotal experiences. The STN occurs slowly but gradually accelerates if corrective actions are not taken in a timely manner.

My suggestion is to reduce your dkh levels by 0.5 daily until you reach a level below 8.0 and maintain it at that level while observing for any positive or negative effects.

[netviper]

For me, i didn't run any bio pellets but my no3 and po4 are constantly zero. Dose biodigest once every 2 water change, running rowa and cheato.

Kept my dkh around 8 n so far, sps seems ok. Was thinking if i should raise or lower my dkh to see if there's better improvement on sps colors.

Bro honkit, any advice?

[honkit]

For me, i didn't run any bio pellets but my no3 and po4 are constantly zero. Dose biodigest once every 2 water change, running rowa and cheato.

Kept my dkh around 8 n so far, sps seems ok. Was thinking if i should raise or lower my dkh to see if there's better improvement on sps colors.

Bro honkit, any advice?

As long as your sps has good colouration and growing, I don't see any need to alter your dkh levels.

[jquek]

My definition of ULNS is a reading of 0.03 or less using a phosphate Hanna checker. Nowadays, I use visual cues such as signs of SPS tissue darkening and the rate of algae growth on my tank walls to watch for any elevations of PO4 levels.

There is no hard evidence that explains why such sps coral tips are stripped of tissue when dkh levels are above 8.0 in a very low nutrient tank but they do happen often enough based on my and others' anecdotal experiences. The STN occurs slowly but gradually accelerates if corrective actions are not taken in a timely manner.

My suggestion is to reduce your dkh levels by 0.5 daily until you reach a level below 8.0 and maintain it at that level while observing for any positive or negative effects.

Thanks for the advice. Will try that. Running out of ideas already.

[jquek]

Thanks for the advice. Will try that. Running out of ideas already.

Sorry to topic starter for "hijacking" this thread. Just a naive question here. My dkh seems constant at about 9.2 ( just tested). I am dosing TLF c-balance 2 parts for Ca and Carbonates and current dosing is 30 ml. For my tank volume, reef calculator tells me that I have to add 27.8 ml to increase dkh by 0.5. So if I want to REDUCE my dkh by 0.5 per day, does that mean I reduce my dosing of second part by 27.8ml? It just seems pretty drastic to me and the last time I did that, I ended up with a huge dkh swing, which is not a good thing. Any advice here?

[honkit]

Stop dosing alkalinity buffer solutions for 12 hours and test your dkh value. That would be your barometer in determining what is your carbonate consumption on a per day basis.

[kira76]

For ULNS tanks with bacterial systems, keep dkh values below 8 to avoid burnt coral tips.

This is interesting. I keep my SPS at kH of about 8~9dkh. But previously it always drops to 6~7dkh. Am now using 2 part system from TLF. Notice that my kh are more stable at 8~9 dkh but also notice some burn tips on some of my SPS. Am running PO4x4 and biopellets.

Any explaination on why is this so?

[honkit]

There have been numerous discussions online regarding this matter and the one that resonates with my opinion is that dkh levels of 6.5-8 and ULNS nutrient levels approximate NSW levels. Thus, dkh levels that are not in this range would cause tissue loss.

[tling]

If my tank is not ULNS, our dkh should not be above 8 dkh? So I need to bring dkh down?

[sunny03]

When you guys focus on kh, do remember to check your ph also

[tling]

My Ph is around 8.2 and 8.3. Anyone know how to bring up or down the ph. I understand by using buffer which affect the dkh also.

[RockyBoy]

Read...

http://reefkeeping.com/issues/2006-06/rhf/index.php

http://www.advancedaquarist.com/2002/5/chemistry