How quickly to reduce Alk?

[Kurkis493]

I'm sitting at 9.5 right now and I'm running ULNS and starting to see some STN on a few pieces. Been dealing with this for a couple of weeks now and when I think I have it under control, another piece will start to STN.

Fairly certain this is not a pest issue.

I would like to drop my ALK down to around 8 with minimal issues.

What do you guys say on this? 24 hours? Longer?

Thanks.

Have PO4 sitting at .05 - .09 but Nitrates haven't been detectable for months.

 

[Touring]

so was it like 7 alk and you brought it up to 9.5 quickly?

or has it been 9.5 for a while and your starting to notice stn? if this is the case i dont think its the alk. but you can drop it down to 8 and it wont affect it. 1.5 a day change is what you want to be around.

i have jumped it up 2.5 alk with no ill affects in a day. the buffer range for coral is 8.0-12alk... thats the resaon i think its not alk but who knows. good luck

 

[Kurkis493]

Well my alk has been sitting at 9.5. I'm having STN problems with less than 10% of my corals but it seems every 5 days another one starts to get it.

My Alk dips between 9.1-9.5 over the course of the day. I manually dose and check alk/po4 pretty much 3x a day to make sure I have those parameters in check.

Everything is checked every couple of days and is within the proper ranges aside from Nitrates which sits at 0.

I have 9 fish in a 60 cube and I do not want to really add more.

My mindset is that with the lack of nitrates and low phosphates, my next option would be to lower alk down to 7-7.5 and see how the system reacts.

I have 70-80 pieces in the tank with probably 8 pieces over the last month and 1/2 that have had some STN problems and of those 8, I've lost 4 after fragging them down.

Right now, I am just letting the tank suck the alk down to 7 - 7.5 and I'll let it hang-out there for awhile and see if that resolves my problem.

I'm just running out of possible problems right now as to why I'm having this happening.

 

[Dog boy Dave]

Probably not your alk. man. Check your RO out put. Confirm under 20 ppm or so. TDS. How long since you changed your membrane?

 

[pocci]

just simply add fresh water to your tank...as much as you need to reduce your alk...

 

[dvanacker]

just simply add fresh water to your tank...as much as you need to reduce your alk...

Bad advice.

I agree with the others. Probably not your alk as long as its stable. RO, temps, lighting...you need to look at other avenues.

 

[dowtish]

But to the original question: The best thing to do to lower is ALK is nothing. Just let it fall on its own. Dont force anything or try to make it happen fast. Depending on your demand it can fall from 9.5 to 7.5 in as little as 2-3 days.

 

[Epicreefer]

I would aim for 7.5-8, 9.5 is not really high but it is the upper range. When you hit 7 that is pushing the minimum and you could see more rtn due to the drop and pH swings. For these reasons and slow adjustments I would aim for around 8 +- .5 for a gradual decrese. Just turn off the alk doser for a day, or reduce dosing 50%, depending on how much your dosing. Just do the math on your alk supplement and water volume to make a 1dkh adjustment or so.

 

[MBMAX]

I would aim for 7.5-8, 9.5 is not really high but it is the upper range. When you hit 7 that is pushing the minimum and you could see more rtn due to the drop and pH swings. For these reasons and slow adjustments I would aim for around 8 +- .5 for a gradual decrese. Just turn off the alk doser for a day, or reduce dosing 50%, depending on how much your dosing. Just do the math on your alk supplement and water volume to make a 1dkh adjustment or so.

great advice. had same problem, very low nutriets and lowered alk. to 7.2 from 9.5 and problem solve.

 

[CBlair]

I just had this exact issue. I was noticing stn on corals after the tips would burn and found my alk was running at about 8.7 dkh. I run an ULNS and was keeping alk around 8. Eventually this started stressing the corals and they stopped growing hence the rise in dkh. Following the advice of some fellow reefers I slowly started adding muriatic acid mixed with tank water into the sump and I lowered it to 7.3, problems solved corals recovered and are looking great. Muriatic should be used as a last resort and with extreme caution as it will cause your ph to drop and is dangerous to you if splashed with it, but it did work well for me with no other adverse affects on the tank.

 

[RKLion]

There could potentially be other issues. Feeding your corals more could help. Just stop dosing and allow the levels to drop to the range you want, it won't hurt your corals going down 1 dkh per day .

 

[D-Nak]

What's your pH? The key is stability. SPS keepers often times have their tanks at 10+ dkh. Get your pH up to 8.3 to keep everything balanced. A sudden rise or drop on dKh is worse than a high or low dKh.