Question about ALK and CA

[cp3823]

So I just got my Aqua controller JR the other night....

Intial PH readings during the day with my fuge being lit 24 hours a day was 8.45

After turning my fuge light off, PH dropped to 7.95 !

So I set my fuge timer to be on a reverse light setting of my main lights and here is what i'm getting...

Day time with main lights on, fuge lights off, PH is 8.25-8.29

Night with main lights off, fuge lights on, Midnight PH is 7.98


is that normal? bad? good? ok? scarry?

Everything in my tank looks great and no problems at all that I can tell.

Oh, SG is at 0.024 ~0.025

[Engine 7]

Sounds normal to me. 7.98 at night is a tad low but not too bad.

[squibley2]

That is a larger PH swing then I would like! Have you calabrated the probe? I would try calabrating it again or checking the results against an actual test to make sure that is what is actually going on. My Tank goes from 8.2 to 8.1 from 3pm to 3am.

[cp3823]

I have never calabrated it. I got the controller used from a member, only 5 months old and the ph prob was taken home to my place in a bag full of water.

also, this is in my 14 gallon biocube if that matters.

also my ALK is 2.5 is that ok?

[squibley2]

Ok a couple of things first of all I would still calabrate the probe! Just cause it was being used does not mean it was calabrated anymore they fall out of calabration and they also get old and need to be replaced and this could certainly happen in 5 months in my experience.

2. Your alk is low so this could cause issues with your Calc and also your PH. I would also like to know what your Mag level is at.

3. Having only 14g of water you are going to find it much harder to control your water params the same way a larger tank does but I still would not want more then a .1 swing in PH but I have never run a tank smaller than 30G so I could just be over paranoid about water stability. Remember the ocean doesn't change much and that is what we are trying to copy so the more stable the better.

[cp3823]

got ya. I'll order the calibration fluid tonight. I do not have a mag test kit, so I have no idea. Calcium is around 420 or so ppm.

[cp3823]

oh, how shoud I raise alk with out going too high? and cheaply?

[squibley2]

Kent makes an alk booster that is ph balance to 8.3 and it is fairly cheap but I would not do anything untill you know what your Mag is cause if your Mag is off then you will never get your Alk and Calc right.

[cp3823]

ok, I'll get a mag test kit.

Newb question

what effect does mag have on the tank?

[cp3823]

would using kalkwasser help any?

[squibley2]

Magnesium will help control some algae and will enable the water to hold the correct levels of alk and calc. Kalkwasser is known as a balanced additive it adds the same amount of alk and calc so if you used that to increase alk then your calc being at 420 already would go off the charts and would precip out of the water and could be bad for the tank.

[cp3823]

got ya. So I need:

PH probe calabration fluid

Mag test kit (which brand)

Kent alk booster?

[squibley2]

Mag test can be from whoever you like, I prefer salifert. As for the Kent stuff I have used it is called "Pro Buffer dKH" and get the one that is PH balanced some people still sell the old one which has a PH of as high as 13 from my tests so you would need to be carefull if you get the one that is not PH balanced.

[Pufferpunk]

I make my own alk with baking soda. I add 50mg/day. Here's the recipe: http://reefkeeping.com/issues/2006-02/rhf/index.php#4

Now you've got me testing my mag... Bring a water sample w/you when you come over & I can test for ya.

[cp3823]

wow, is it just me or it it kinda confusing and kinda scares me to make my own alk? I just dont wanna crash my tank. Plus, I only have a 14 gallon tank, so a huge bag would prolly last me for like what? 15 years lol?

[Pufferpunk]

LOL, I used to be terrified of all that stuff too--all you need is a box of baking soda. You have to scroll down for the alk recipe. A fellow reefer here, talked me thru the whole thing (thanks Beefy!).

[cp3823]

cool, I just need to read and re read it. I'm just concerned about using that in a 14 gallon tank. I'm hoping to be getting a 29 gallon and do a 10 gallon sump so I would have more water volume, but I need to get my stuff straightned out first on my current tank before I spend time on a larger one.

off topice the weekend of the 19-20 I finally have off so I gotta sweet take the g/f so i came take the drive up your way :-)

[Pufferpunk]

Sounds good, I believe the CMAS meeting is on the 19th.

[cp3823]

oh sweet ^^

[mnestroy]

If we are talking a 14 gallon tank, how about just a series of water changes? If alk is low wouldn't doing a few large changes get things back in check? (assuming the fresh salt water is in check)

I've hear many people who don't dose at all, they just do water changes more often.

[cp3823]

I usually do a 4 gallon water change every two weeks. I could check the params of my fresh saltwater. I guess thats a good idea. I never thought about that.