Help! my dkh keeps dropping!

[RAV-65]

hi all,

my dkh seems to be dropping all the time... i've tried using reefbuilder to increase it but everytime I stop, it starts dropping. I only add Salifert's Iodine , DT & AZ-No3 to my tank... The dkh is currently at 5.5-6.0, my calcium level is 440. I do not add calcium.

Can someone advise wat's going wrong? is it supposed to be like dat and also someone mentioned a lack of magnesium, izit true?

Vincent Ho

[Tigger]

I have the same problem too

[Fireclown]

You might want to check your calcium again, low calcium can cause your Kh to deplete rapidly. I'm encounting the same problem now.

[Chris]

I think high calcium then will cause dkh to fall.

Low PH may be the reason that dkh cannot go up.

correct me if I am wrong.

[ahkit81]

i dont think that high calcium level will make the dkh to drop.. my calcium level is high around 500+ but my dkh level is around 11

since i drop the kalk into my tank the dkh level is around 12 it never drop unless i do a water change ....

any idea of there is a relation of high calcium make dkh to drop?

[jc85]

Apparently, PO4 remover will cause a drop in pH and Alk too.

I started a another thread to ask for comments on this issue cause I do experience the drop in Alk after using PO4 remover. Before that I do not have to use any buffer at all.

Cheers

JC

[madmac]

hi all,

my dkh seems to be dropping all the time... i've tried using reefbuilder to increase it but everytime I stop, it starts dropping. I only add Salifert's Iodine , DT & AZ-No3 to my tank... The dkh is currently at 5.5-6.0, my calcium level is 440. I do not add calcium.

Can someone advise wat's going wrong? is it supposed to be like dat and also someone mentioned a lack of magnesium, izit true?

Vincent Ho

Vince,

This is what I think happens to your tank. I must qualify myself fisrt because I quite new still.

In WetWebmdia.com, there is very good coverage on pH, Alkalinity (or dHK) and Calcium (Ca). Your understanding of this will get you far in this hobby as it forms the basics of good water parameters. The pH coverage is here : http://www.wetwebmedia.com/marphalk.htm.

Firstly, what dKH test kit are you using? Is there another dKH to test against the first, just to make sure they are both giving the same result.

2ndly, what is your pH level now? It could be dangerously low for your LS.

As for your pH, I think it is due to your heavy stocking of live fishes (for your tank size)... and the accumulation of CO2 in the water column, CO2 turns water to Carbonic Acid, which lowers the alkalinity of the water(obviously). At night time, pH has a tendency to drop as the plants/algae which takes in CO2 in the day suddenly compete for O2 and give out CO2 instead, adding more CO2 in our water column together with your other LS. So that explains why some prefer to dose in the night.

There's nothing wrong with your system. Keep maintaining your biweekly dose to keep your pH constant.

I'm not too sure how Ca affects your pH, except that for every "x" volumn of water, you can have a certain amount of hydrogen/Ca/etc molecules. This portioning isn't very strick, it can be a slight varible, but if any of the elements exceed their respective set, it will precipitate out as something insoluable, i.e. visible particles floating around your water. However, if your H+ ions is low, it allows your Ca to increase, hence, your high Ca level... (actually 440 isn't very high for those keeping SPSes-- I think)

Hope tt helps, happy keeping,

mm

[FuEl]

Coralline algae can cause kH levels to drop very fast. Check your magnesium levels. Low magnesium levels can lead to difficulties in raising kH. If manual dosing upsets you...there is always the Calcium reactor. You'll need one sooner or later.

[AlfaRomeo]

Does CR help in replenishing Magnesium too?

[FuEl]

Does CR help in replenishing Magnesium too?

It depends on the media you are using..if you're using ARM from Carib Sea it should also liberate the proportionate amounts of magnesium, strontium and other trace elements. This is because the media came from past living organisms, which took up these elements in the proportions that were needed by them. When they die these elements are enclosed in their shells and when the shells are dissolved, the elements are reintroduced back into aquaria.

[patrick123]

I have the same problem. My calcium is 400mg/l but my Kh is 6dkh. Is this level dangerous? I'm currently using rowaphos and kalkreactor. No additive or CR yet. Should I use reef builder to raise my kh?

[RAV-65]

Wow...

thanxs for all the advice... i did some of my own research, and concluded that High Calcium does not increase your dkh, in fact when your calcium goes up, the dkh drops... My testkits are by Salifert and I've noticed this problem for a while, maybe I should get some magnesium additives.

The phosphate removal concept which depletes dkh is interesting... but anyone can confirm? I use lots of kontraphos...

But i realise my calium drops very slowly, 10ppm after more than 1 week... will increasing the dkh cause the corals to absorb the calcium faster?

Vincent Ho

[madmac]

I have the same problem. My calcium is 400mg/l but my Kh is 6dkh. Is this level dangerous? I'm currently using rowaphos and kalkreactor. No additive or CR yet. Should I use reef builder to raise my kh?

Patrick,

a dKH level of 6, "Is this level dangerous?" is a wrong question. A dKH level is simply a measure of alkalinity, or "pH buffering". The normal accepted level of alkalinity or dKH is somewhere about 10 to 12 times. Even at this level of 6, if your pH is btw 8.1-8.3, then it is not dangerous. However, if it simply points to a condition in water, which will allow for wild fluctuations in your pH, i.e. you can have a pH as low as 7.5 quite easily on say normal water evaporation during the day.

A higher pH means that it takes alonger time for your pH to swing, it remains constant at say 8.1 for 3 to 4 days before it starts to drop. I hv read that some additives can cause a drop in your pH, but again a higher buffer will s l o w the drop.

Now if your LS can take a low pH then u don't have to worry, however, since you say you're using rowa and KR, chances are.. you're keeping stoney corals, which wouldn't be tolerable to low pH. I'd say, the problem lies with your KR, it needs some fine tuning.

mm

[RAV-65]

Patrick,

a dKH level of 6, "Is this level dangerous?" is a wrong question. A dKH level is simply a measure of alkalinity, or "pH buffering". The normal accepted level of alkalinity or dKH is somewhere about 10 to 12 times. Even at this level of 6, if your pH is btw 8.1-8.3, then it is not dangerous. However, if it simply points to a condition in water, which will allow for wild fluctuations in your pH, i.e. you can have a pH as low as 7.5 quite easily on say normal water evaporation during the day.

A higher pH means that it takes alonger time for your pH to swing, it remains constant at say 8.1 for 3 to 4 days before it starts to drop. I hv read that some additives can cause a drop in your pH, but again a higher buffer will s l o w the drop.

Now if your LS can take a low pH then u don't have to worry, however, since you say you're using rowa and KR, chances are.. you're keeping stoney corals, which wouldn't be tolerable to low pH. I'd say, the problem lies with your KR, it needs some fine tuning.

mm

Wah liao... very cheem...I blur liao...

[planetg]

CA and KH levels depends very much on your lifestock.

A Calcium Reactor does not necessarily raises CA or KH. My experience is it does best at maintaining levels. So if you uptake is crazy (i.e. mama clams, tons of sps, etc..), it is likely the levels will drop without additives.

Low KH will then induce PH fluctuations.

One of the course of action as such is to raise KH with additives such as Reef Builder and if necessary raise Calcium only by using a calcium only supplement such as calcium chloride (Advantage Calcium). Kalkwasser or calcium hydroxide is not useful for this purpose.

Kalkwasser, like Calcium Reactors with proper media are forms of balanced supplement, excellent for maintaining levels but not that effective in pushing either levels up. Well i base this fact on my personal experiences and from reefers I talk to.

So for those with non-ideal CA and KH levels, dose supplements according to instructions and use Kalk or CR to sustain them well.

As for me, I'm still trying my a** off to get the right balance. Will I get slapped to say that I can never get my KH past 7.5dkh but what the heck, as long as as my mama clams are growing and things are staying so much alive, gotta enjoy reefin and not be bothered with those figures!

Feel and understand the reef, not only the maths behind

[reef2]

having a CR can solve kh and ca problem unless its oversized for your tank. if it is x5-x10 oversize, then you can tune the kh level up or down, else it can only maintain it. worst, if yr CR is not sized for your tank, yr kh will still drop. clams and SPS are very hungry for kh and Ca, so a 3 footer SPS+Clam tank = 5-6 footer mixed reef. dosing kh and ca is like a slave to the tank

[planetg]

yup. what u mean is that getting an oversized CR will do the trick right?

strangely, i know some reefers with extremely large systems but still slave to the tank. jia lat hor... maybe then again it's still not large enuff.

shit! having this hobby is already a slave to the reef system but we are voluntary slaves so cannot complain! haha

[alanseah]

no only just voluntary... worst u paying for it...

[reef2]

so worst than proxxxx in geylang rite ? work and pay, not paid

[patrick123]

having a CR can solve kh and ca problem unless its oversized for your tank. if it is x5-x10 oversize, then you can tune the kh level up or down, else it can only maintain it. worst, if yr CR is not sized for your tank, yr kh will still drop. clams and SPS are very hungry for kh and Ca, so a 3 footer SPS+Clam tank = 5-6 footer mixed reef. dosing kh and ca is like a slave to the tank

Is there a guideline as to how to determine whether the CR is right size, undersize or oversize for your tank?

Is it always good to have oversized CR? And when a CR is oversized, and if not tuned properly, will the Ca and Kh be raised to a dangerous level along with the CO2?

[planetg]

i guess it pretty much comes with experience to select the right size for your tank. cos consumption really varies from tank to tank.

a good guide is to get the specs for those commercial CRs and stick to the upper limit. (i.e: if it recommends for 400-800litres, it shd be decent enuff for 800litres)

as for DIYed CRs, find one equivalently sized commercial CR and make that estimation.

for tanks that are not so fully stocked, kalk drip or a kalk reactor coupled with a auto-topup is a good alternative as it avoids the trouble of tuning and it solves the issue of topping up evaoprated water. many reefers run a kalk reactor together with a CR as well.

go look for tubby (auto top up) and cookiemunster does Kalk reactor as well if u are opting for kalk reactors. as for calcium reactors, they are a couple of nice guys here who sell them too.

[patrick123]

Already have the kalkreactor from Cookiemunster liao. Now considering the CR. The problem is people always recommend me to go for the biggest CR, and the biggest one does not fit into my cabinet. And I don't want too many thing sitting outside of the cabinet.

[planetg]

actually i'm running a 4x2.5x2.5 mixed reef with 2 mama clams, 1 med and 2 small clams + 10 sps colonies.

my CR (4" diam 55cm tall) cannot keep up with the intake which is why i'm desparately trying to build a 2nd chamber and get the KR going!!! haha.

maybe some specs of your tank and inhabitants will allow many reefers here to guide.

[patrick123]

My tank is 6x2.5x2.5 and I'm keeping mostly LPS, soft corals, 2 anemone, 2 clams.

My calcium is around 400mg/l and kh is around 6dkh. I'm running the KR right now through the auto top up.

Any suggestion?

[reef2]

i guess it pretty much comes with experience to select the right size for your tank. cos consumption really varies from tank to tank.

a good guide is to get the specs for those commercial CRs and stick to the upper limit. (i.e: if it recommends for 400-800litres, it shd be decent enuff for 800litres)

as for DIYed CRs, find one equivalently sized commercial CR and make that estimation.

for tanks that are not so fully stocked, kalk drip or a kalk reactor coupled with a auto-topup is a good alternative as it avoids the trouble of tuning and it solves the issue of topping up evaoprated water. many reefers run a kalk reactor together with a CR as well.

go look for tubby (auto top up) and cookiemunster does Kalk reactor as well if u are opting for kalk reactors. as for calcium reactors, they are a couple of nice guys here who sell them too.

a good guide is to get the specs for those commercial CRs and stick to the upper limit. (i.e: if it recommends for 400-800litres, it shd be decent enuff for 800litres)

=> if its Deltec, i may agree according Max's review in RC. but if its other brand, i can safely say that for a full sps+clams tank, x5 to be safe for the upper limit.