high alk supressing calcium

[eric gregory]

hello i'm having problems with calcium. my tank is a 230gal sps reef that's 2 years old. the problem i'm having is i can not get my calcium up.i've only had this problem for the last 6 months. my alk is high which is making my calcium chronicly low. i've tested my magnesium and it's like 1250 alk is 18-20 and my calcium is 275-295. my corals are starting to loose there colors and growth is dramaticly slowed.
i've done 2 water changes of 100gals 1month apart with no change. i've tried using two part additives, dripping kalk 24hrs a day, put a ton of liquid cal supplement in and still low calcium level. and i k2r reactor.
tank description is 230gal sps reef with 60gal sump. dsb~4-5 inches of caribsea gravel(the kind you use for dsb)300lbs fiji live rock, 2 400w 10k ushio, 1 250w 6500k iwaski, 3 6ft vho actinic 1 6ft daylight bulb, 2 40w actinic for dawn and dusk. ets800 skimmer,k2r calcium reactor effluent is 6.5- 6.8 steady drip almost a stream,that empties into a cup before entering tank.10 gal sump for kalk to use for top off that runs 24hrs a day delvering about 2 1/2 gals. 1/2hp chiller temp 78-80, ph during the day ~8.2 ph at night~7.9-7.85. and yes the probe is right i've calibrated it three times with three diferent solutions. so also i don't under stand why my ph drops low at night with my hihg alk. all water is ro/di.
please help me i do not know what to try next or a direction to look in i'm out of ideas.
thank you for your time eric gregory

 

[jsteinman]

Dont' know if this will help, but I had my Alk inthe 18-19's and did one half gallon with 15 ml of 5% Vinegar and the next day it was down quite a bit. It may be work a try.

On another note: How do you fit all that light into your tank?

I am currently running 8x 96 w PC's and am going to switch over to 4x 250 w 10k HQI's that I have in the garage and still run 4 of the PC atinics. I am trying to figure out how to fit everything on top of the tank. Just wandering what you've doen to overcome the spacing issue. My tank is 8' x 2' x 2'.

 

[eric gregory]

i don't really want to vinegar in the tank after reading the thread RANDY HOLMES-FARLEY put up today. i have not put vinegar in so far and i hope not to. but if that's what it takes i'll do it. i had hoped that RANDY would have had some great insight on my tank he really sounds like he knows what he's talking about.
as far as the lighting goes it was easy to put in my canopy 'cause it's 24inches wide. the three halides run down the center being centered into 1/3 sections and the 6 floresents run three on each side of the halides.

 

[esmithiii]

Bigreef: Re-read Randy's post. The amount of vinegar suggested is quite low. Randy is not saying that vinegar is bad, just that if you dose heavy quantities of it your test-kit readings of Alk might be higher than what is really in your tank.

Also, this is a pet peeve of mine, but I think it merits mentioning: Try to get in the habit of putting the units of measure with your test measurements. I mean, do you have 18-20 Meq/L of alk or 18-20 dKh? Its like saying that my car is really fast! It will do 180! (km/h that is)

The reason your pH drops at night is that your lights aren't running, and algae (even the stuff you can't see) is not converting CO2 into O2. I run a reverse cycle refugium for that very reason.

One thing you can do to raise pH is to aerate the effluent from your calcium reactor before it goes into the tank. This helps dissapate some of the CO2, which raises the pH.

Ernie

Ernie

 

[eric gregory]

sorry about that esmithiii it was a bad overlook on my part. i should have included a unit of measurement. i just checked the alkalinity again and it was 6meq/l or 16.8DKH.
i understand why the ph drops at night but i thought that having high alk would act like a chemical stop per say or a limiter to how low the ph could drop. if i'm wrong please explain!! i just thought that a ph of 7.85 was kind of low for an alkalinity that stays this high.
also how much vinegar would you recomend to put in my tank? total water volume is ~240-250gals. should i dilute it in ro/di water or just poor some in slowly?
i'll try to more percise on my questions and descriptions in the future. thank you again eric

 

[eric gregory]

also i thought about running my effluent through my protein skimmer but was worried that it was going to skim out the elements that were beind disolved from the media.