Ca+, dkh/alk, ph question????

[hlama]

hey everyone been adjusting the Ca+, dkh/alk, ph. will give the going ons during the last month. tank is only 3 months old. i do all readings before the water change.

6-7: temp=79, sal=1.023, Ca+=428, dkh/alk=12/4.3, ph=8.2, 5gal water change.

6-15: temp=82, sal=1.023, 5gal water change.

6-21: 5gal water change. added 65lbs of fresh live rock to 100lbs of cured rock already in the tank for 2 months. tested this 12hours after. temp=80, sal 1.023, Ca+420, dkh/alk=14/5, ph=8.2, added 55ml of calcium chloride to bring the Ca+ in balance with the alk. over the day not all at once.

6-22: 5gal water change
6-23: temp=79, sal.=1.024, 5gal water change

6-24: temp=80, sal=1.024, Ca+=468, dkh/alk=12/4.3, ph=8.0, NH3=1.0+(off the cart), NO2=0.5, NO3=0, 10gal water change added carbon.

6-25: temp=80, sal.=1.024, carbon removed.10gal water change

6-26: temp=79, sal=1.024 ph=8.0, NH3=0, NO2=0.3, NO3=20. 10gal water change

6-27: temp=80, dkh/alk=11/3.9. 10gal water change

6-28: temp=78, sal.=1.024, Ca+=444, dkh/alk=11/3.9, ph=8.0 NH3=0, NO2=0, NO3=0 (7 day cycle not bad). 10gal water change.

7-2: gone for the holiday

7-6: temp=79, sal.=1.025, Ca+=432, dkh/alk=10/3.6, ph=8.0, 0 on all others. 5gal water change.

from what i think i know, everything is all good. i want to add more calcium chloride to boost my Ca+ up to 450 and bring up the ph and lower the dkh. mainly worried about the effect on the ph. i think the high alk with the lower ph is ok. but the thing is as the Ca+ and dkh come down the ph remains steady. by adding calcium chloride what will the overall effect be. any thoughts.

Your PH is fine. To hold a 450ppm calcium you should really bring the alkalinity up to around 12.6dkh. The balance between alkalinity and calcium should be maintained as much as possible. I would also keep the specific gravity up to 1.025.

Here's a calcium/alkalinity balance chart...

Alk meq/L___Alk dKH________Calcium ppm
0___________0_______________360
0.5_________1.4______________370
1___________2.8______________380
1.5_________4.2______________390
2___________5.6______________400
2.5_________7_______________ 410
3___________8.4______________420
3.5_________9.8______________430
4___________11.2_____________440
4.5_________12.6_____________450
5___________14______________ 460
5.5_________15.4_____________470
6___________16.8_____________480
6.5_________18.2_____________490
7___________19.6_____________500

Also, I'd turn up your heaters so the tank stayed a constant 80deg. A 2deg fluctuation isn't that bad but it's not ideal.

[MikeS]

What's your SG currently at? and your Mg?

Also, be aware that Ca levels over 420-430ppm, while good for quickly building the coral skeleton, can actually hinder coral tissue growth...

Mike

[hlama]

thanks for the replys. SG at 1.025 just brought it up slowly. getting the Mg kit this weekend. i use IO salt mix so i pretty sure the Mg+ is around 1000 based on pasted experience. not add till i get the kit. just 5 chromis and the rock in the tank. and 4 crabs plus i have been populating the tank and the sump with mysid and pods and thing from my other tanks. just added my macro a few days ago. think this will take care of the ph. just getting the coraline going. i brougth the Ca and ALK in balance already a while ago thanks though. lol the tank has no heater and the lights are only 40 watters for the coraline. my issue is keeping the temp down. fixed this with DIY wanabe chiller. thanks for the heads up. decided to do nothing and watch it till Ca+ and dkh =410ish and 8-9. then dose with tropic marin bio-cal. the next time i do my ph i will check for excess CO2 if it is still around 8.0. i know it is ok but i dont like it that close. the ph should have gone up when the dkh and Ca+ came down right? so my guess the ph might be do to excess CO2. hopping the macro took care of it as today i c lots of new thaules. been out and have not tested since the 6th. will let you what results tomorrow bed time right now.

[hlama]

hey guys just checked my ph this mornning and it was 8.1. ahhh happy now. back on the weekly water changes. will test everything in a few days before i do the water change. if everything geos well or at least as expected will start testing monthly till i start to stock the tank. thanks for all the help.

[MikeS]

. the ph should have gone up when the dkh and Ca+ came down right? .

It depends...in a very basic sense, alkalinity is what keeps pH stable...ie the higher the alk level, the better the solution will resist a negative shift in pH. The CO2 issue is likely...the macros might help that a bit...but so will the addition of an airstone in the sump.

Mike