KH is higher at night then during the day ?

[Sailfinguy21]

Checking my KH tonight its 3am and the lights have been off 5 hours now. The dkh was 11, i checked it twice and with another kit and its 11. I had tested the DKH earlier in the afternoon and it was 9.5, i didnt dose today either.

Is this normal for the kh to jump at night ?

 

[smartwater101]

Alk is consumed at a higher rate with higher pH. So your Alk # will be higher at night when pH is low.

That said, if you didn't dose, the jump seems strange. You did two tests at night, but did you do multiple tests earlier? Maybe a small water change? I'm betting the first (day) test was off.

 

[Sailfinguy21]

No its always 9.5-10 i normally dose 16ml of part 2 seachem every day for alk in 135g tank. I decided not too today because im noticing a few acroporas melting on the tips. Mag is 1380, ca is 440, ph earlier today was 8.0-8.2, i didnt check the ph tonight..

havent done a water change in maybe 3 weeks. I cant explain why a couple acroporas are doing this or why the jump in alk when the lights were off. Ill check alk again tomorrow, i check every day during the day but ive never done it at night. Curious if itll swing again tomorrow night

 

[Sailfinguy21]

checked ph. its 7.6-7.8, was 8.0-8.2 in the day

 

[Sailfinguy21]

Im wondering do you think this is causing the acros to melt slightly on the tips. I know a alk swing can do it. But im wondering if its at 9.5 without a dose and 11 at night. Then 10 with a dose would be 11.5 almost 12 probsbly ?

Ill try it out tomorrow and see. Maybe i need yo let the alk drop a little from 10 to say 8.5 in the dwy so it isnt so high at night ?

I dunno. Just trying to figire out why the melting tips

 

[smartwater101]

Most believe the melting tips is caused by high Alk with low nutrients. High Alk is fine but if you don't have the nutrients to support it, the tissue can't keep up with the skeletal growth, hence the white tips.

What are your Phosphate/Nitrate levels?

I run alk ~9.6 and try to keep my Phosphate at .05 - .08 and my Nitrates at 5 - 10. Milage will vary of course, but don't keep them at 0 if you're having issues.
(Or, if you prefer ultra-low-nutrients, simple keep the Alk lower.)

I'd keep testing over the next few days. Several times to get an idea of how your parameters shift throughout the day. Don't dose just yet, wait till you have a better handle on the trends.

 

[Sailfinguy21]

Most believe the melting tips is caused by high Alk with low nutrients. High Alk is fine but if you can't keep the nutrients up, the tissue can't keep up with the skeletal growth, hence the white tips.

What are your Phosphate/Nitrate levels?

I run alk ~9.6 and try to keep my Phosphate at .05 - .08 and my Nitrates at 5 - 10. Milage will vary of course, but don't keep them at 0 if you're having issues.

I'd keep testing over the next few days. Several times to get an idea of how your parameters shift throughout the day. Don't dose just yet, wait till you have a better handle on the trends.

If i dont dose alk drops by nearly 1.0 a day, in a few days itll be really low, same with calcium i have 60 corals in the tank some the size of basketballs most just frags.

Nitrates today were around 5 maybe 10ppm, phosphates my normal kit is empty but the API kit shows 0.

The white tips isnt what im mentioning i see that on all the sps corals , i mean the tips melt. I can see stringy strands on the tips of a couple acros, ive seen this before and if i let it go on long enough you notice its actually the flesh melting off the tips

 

[smartwater101]

If you're usually running 9.5, at least don't dose till the levels get back closer to that level.

Confirm your Phosphate readings and consider bringing them up a bit. 9.5 Alk and 0 Phosphate is something I'm definitely not a fan of. I've had similar issues, to what you're seeing, for this reason.

 

[Sailfinguy21]

So what alk do you recomend i let it drop too, same with cal ?

 

[smartwater101]

If you've had success with 9.5 then it's probably fine to continue with that (with of course some Phosphate) but it's ultimately up to you. And if you're really concerned, it could be time to slowly shift to a lower Alk system.

 

[Mortie31]

In my tank my corals consumer ore ALK during the day than at night so I always see an small increase at night of 0.2dkh. Your swing is larger than that though. How many times a day do you dose your Seachem?

 

[Sailfinguy21]

once and i didnt dose it today like i said

 

[Mortie31]

once and i didnt dose it today like i said

I’d try spreading your dose out more evenly especially during the lighting period, the swing your getting is due to alk consumption.

 

[Mortie31]

How long has this swing been happening, if your seeing damage to your corals as you say then that will reduce ALK consumption further and increase levels even more. How old is the system?