dkh from 11.3 to 9.3 in a week?

[spscrackhead]

the setup is a 30 gallon. i have just a few frags. sps, agans, zoas. all look fine. gonipora isnt opening tho. i was dosing vinegar. after these results i plan on stopping till things settle. was wondering what you guys thought it could be

 

[m and m]

Well first off doesn't vodka/vinegar dosing need to be under like 9dkh I believe? Second I would say error in test or you did a wc and the salinity was off and dropped your dkh

 

[VegasRick]

If coraline algae growth is good it could drop that amount in a day

 

[aquabull]

Agreed on corraline and potential coral growth consuming it through calcification!

 

[Stoneyj33]

Well first off doesn't vodka/vinegar dosing need to be under like 9dkh I believe?

+1 you will have to dose alk a all the time to keep it above 10 and carbon dosing. How long have you had this set up? Are sps randomly getting white tips then dying, lps shrinking untill they disappear?

 

[Brettinteriors]

Yep, if I don't daily dose my Dkh would drop by about .5 a day. Also, adding too much calcium will lower kh. I find nine to be the sweet spot and that is what I shoot for. More important is to have a steady Dkh. I add my carbonate powder to my topoff water. That way it is added throughout the day every day.

 

[spscrackhead]

no water change. 11.3 is what my salt mixes to. top off is consistent (tunze ato).
you guys are saying by dosing vodka/vinegar it also lowers my dkh?

 

[Brettinteriors]

My understanding is vodka has no effect on Dkh. I dose carbon. Vinegar lowers ph but I dont know about Dkh. When corals build skelotons they in essence use the carbonate which is what Dkh is. Lay terms. Coralline too. What you want to avoid is the roller coaster between you Dkh and calcium. Dkh gets too high it will lower your calcium, calcium gets too high it will lower your Dkh. This is why I shoot for a consistent Dkh of nine and calcium of 450. A good healthy tank of stonies will eat up your Dkh. consistent Dkh levels will help with consistent growth and use of Dkh. If you Dkh fluctuates a lot you will have ph swings. Also, my coral growth slows if it isn't consistent and this changes the Dkh use. finding the sweet spot is the key. I tested every few days for a while and figured what my average daily use is. In my case .5 Dkh.. I by my carbonate from bulk reef supply. They have a calculator on their site that tells you based on your water volume how much to ad to raise the Dkh to the level of your choosing. In my case it is 1tsp of the dry powder daily. I get very little to no fluctuation weekly. I test 1 time a week. As things grow my use will go up. It is important to dose Dkh slowly as it raises your ph temporarily. Drip it in or add it to your top off. Calcium is similar in the sense you don't want to add to fast. My calcium goes down aprox 15 ppm daily. But raising your calcium more than 50 ppm in a day is a big no no. A while back I killed a sps of some sort because I raised the calcium 70 ppm in a day. Again why I daily dose now. Sea water Dkh is much lower. Like in the 7s if I recall mayby lower. Salt mixes have higher Dkh to make of for the average reef guy not dosing. in a tank without stonies water changes would most likely be enough to maintain a reasonable level of Dkh. Acro does better at a lower Dkh too.

 

[mcarroll]

no water change.

Firstly, I wouldn't predict too much Alk-oriented trouble until you get down to around 7dKH - depending on what else you might be doing to make pH problems with the vinegar dosing. (e.g. dosing vinegar at night or early morning when the pH will already be naturally depressed for example) The tank is more susceptible to pH swings the lower the Alk. With respect to others' opinions, I would adjust your Alk up to 12dKH when you test and let if fall from there. (420 Ca and 1320 Mg seem to be a good match for that Alk level. Read the dosing sticky in this forum for some tips on dosing techniques....precipitation shouldn't be an issue.)

A few questions:

• Do you use RO+DI water for salt mixing and top off?
• What are your lights and if not LED, how old are they?
• Are you dosing vinegar preventatively or are there currently other issues with the tank that the vinegar is intended to treat? Vinegar should be pretty optional in most scenarios.
• Are you a little overstocked with fish?
• Do you run a protein skimmer? What skimmer? What pump? How would you describe its performance?
• How old is this tank and how old/big are your stony colonies?

Unless your stony corals are pretty big/quite numerous....
...the consumption of Alk in a tank that size shouldn't be very much. Your testing may be wrong, but more likely Ca or Mg or both are a little off, which will give you unexpected results on Alk tests. I'd recommend that you focus on 10%-per-week (2.5 gal)water changes with a nice salt like Reef Crystals until your numbers are in line. (Do five 2% (.5 gal) water changes per week if that's easier/faster - your corals will love it. Could go up to 20% per week or so if you have to compensate more Ca/Alk loss.) You probably won't have to worry about dosing more than once a week or so - for a while at least - once your water is dialed back in.

Make sure you have some two part ingredients on hand for when adjustments need to be made. Think of Alk and Ca supplements for your stonies the same way that you think of food for your fish: They'll die without it, and you rarely if ever forget to do it for that reason. And it's no big deal feeding your fish, right? And unlike feeding fish, to your advantage, there are actually tests to let you know if you're "feeding" your corals enough, and you can avoid some of the "manual feedings" just by doing more/bigger water changes!

If you buy commercial additives (which I would suggest at the beginning) I recommend Brightwell to start with because they have the overall best instructions on the bottle to help you understand what/when/why to dose based on your testing results. When you're into a rhythm and using a lot of product, there are a lot of good bulk supply options that will save you money - I just don't recommend starting there if you aren't already comfortable dosing based on your testing. For testing I recommend you at least have Salifert Ca and Alk test kits on hand and run checks weekly or more often at first...later you will be able to scale back to much less frequent tests.. Any other kits are optional.

Good luck!

-Matt

 

[spscrackhead]

thank you for all your input guys
ok i guess i will start off answering the list of q's

• Do you use RO+DI water for salt mixing and top off?
• yes i do
• What are your lights and if not LED, how old are they?
• they are brand new ai sol's... so led
• Are you dosing vinegar preventatively or are there currently other issues with the tank that the vinegar is intended to treat? Vinegar should be pretty optional in most scenarios.
• the vinegar is optional in my case. and i would consider it mostly preventative.
• Are you a little overstocked with fish?
• 2 clown, 2 chromis
• Do you run a protein skimmer? What skimmer? What pump? How would you describe its performance?
• i run the tunze 9010, i find it to be working decent. i dont think my tank has much bio load to really work it like it can be. whenever i put my hands in the tank or feed any frozen food it looses its foam head but then eventually builds back up.
• How old is this tank and how old/big are your stony colonies?
• i wouldnt say i have any colonies, all frags for me. so they are all small

i have the brs kalk kit on hand;

Kalkwasser, Calcium Chloride, Sodium Bicarbonate, and Magnesium Chloride. the plan is to eventually does kalk and vinegar with the top off(and anything else i run low on). honestly i don't know where my mag is. i have salifert ca and alk kits. but my calcium is 500. this is how my oceanic mixes. i am not to fond of this salt so i plan on switching once this batch is up. i would be really surprised if the corals were using this up, as i dont see much growth (most frags are new and still settling).

how often do you suggest testing at first to base what my dosing needs are? every 2 days?​

 

[Brettinteriors]

Calcium at 500 could lower your alk. Think of water as a cup of marbles. If you put too many of one in you push another out.

Just FYI sodium bicarbonate will not raise your ph like sodium carbonate does. I think brs states itnwill slightly lower it.The only reason I point this out is that you are dosing vinagar which can lower ph. I recommend vodka or biofuel.

 

[Stoneyj33]

Don't raise your alk! Your carbon dosing, keep it at 8 or lower.

Do you see random white tips in your sps and lps shrinking? How has your calcium levels been fluctuating?

I'm going to guess the answers will be, yes and haven't had to dose calcium as it remains higher than optimal levels.

 

[spscrackhead]

nope, i have not been dosing anything at this point, the levels from the salt are so high. the calcium has been anywhere form 480 on up past 500 (the kit maxes out at 500). lps are fine, growing and all, except for my gonipora, hasn't been out in a week or so. and no, no random white tips.i had 2 sps die from rtn, the rest seem fine tho.
i have been testing my alk for the past few days, once every 2 days. and for the last 4 days it has been steady at 11.2.... i did a water change and i am assuming that brought it back up to the 11s. i really think i need to toss this salk

 

[spscrackhead]

why should dkh be 8 or lower when carbon dosing

 

[Stoneyj33]

When carbon dosing your stripping your tank of nutrients, therefor the zooplankton has nothing to feed on to thrive. Once the zooplankton is absent your corals struggle to thrive.

At the same time your running parameters outside of the natural ranges with hopes to increase growth. However without a food source it stresses the coral out more not allowing it to consume the alk and calcium in order to build a skeleton. Thus your coral begins to recede until it is dead. I'd never recommend alk being higher than 10.

I'd lower your alk to 8 calcium to 400-450 and start feeding zooplankton and over feeding your fish.

 

[acan lord]

Good luck, hope things work out.

 

[mcarroll]

why should dkh be 8 or lower when carbon dosing

Certainly 8 is a safe place for your alk to be, but I'm not sure I could advise doing anything to actively get it down that low if your salt mix is higher (which is expected with yours). I think the Oceanic salt's wildly elevated calcium levels might be making the alk read lower than expected when you're on the low end before a water change. I might consider laying off the vinegar-as-preventative too...while it might not hurt, there should be no real call for it at this point. Later though...

Geting back to your original situation...if water changes (or even better a water change) did the trick, then you are in good shape.

What you need to do now is establish what your alkalinity is getting down to right before your water change. If it's not getting lower than 8 dKH, then I'd say you're fine with water changes and the existing salt (or something like Reef Crystals as a replacement).

However, it sounds like you have a bunch of frags just waiting to take off, so keep tabs by testing weekly once you notice coral growth as you really do not want your alk to fall below 7 dKH or so. Sometimes it's not that bad, but other times you can get get die-off from the side effects. Don't risk it.

Once you start regularly seeing 8 dKH or less show up on your pre-water change tests and you can't do more/bigger water changes (10% per day is no problem for the tank) to compensate, it's time to engage the kalk+vinegar (told you it'd be back later!) in your top off bucket and measure that effect. (Go slowly!) In theory you can address 100% of your calcium and alkalinity needs with vinegar+kalk (as linked) but in reality most people don't push that system and add manual additions of calcium chloride and Arm & Hammer baking soda to their dosing regime. Do not try to avoid getting a doser of some sort for your two-part...eventually you will forget to dose too often or have to be away and something in the tank will die/suffer. Dosers can be had for around the cost of your Tunze ATO or far, far less, depending on the features (mostly level of automation and calibration) you select to buy.

-Matt