balancing act with #'s

[elaw62]

having alittle trouble getting my #'s to balance out. Calcium was too high, around 560. Dkh was at 7 and I had no way to test Mg. Just started manually dosing alk. part of 2 part slolution and have been doing so over a month. Also carbon dose vinegar at 15ml. a day. tested again yesterday and #'s still off a little but getting better with the exception of dkh. I now have test kit for Mg. so #'s are as follows.
SG-1.023 (too low, did water change over weekend and didn't quite replace enough saltwater so ATO kicked in a little too much. Slowly bringing level back to 1.025)
Ca-520 (better: would like around 450)
Dkh-6 (worse: maybe due to low SG from wc)
Mg-1200
Tank is a 90 gallon with 30 sump. ATI-6 lamp T5 for lighting.
livestock
yellow tang
copperband
orchid dottyback
eyelash clarkii
falme angel
auriga damsel
small bubble tip anemone
various inverts, soft & LPS corals
only 2 SPS (ink birdnest & stylophora;i think that's correct)

[Randy Holmes-Farley]

Are you asking advice on how to proceed?

How much of what alk supplement have you been using?

[ek9vboi]

First step would be to get the Mag in line at 1350-1500, I prefer 1400-1500. It doesn't hurt to have a high level of mag.

Second, dose alk only for the time being. Follow the BRS calc and dose accordingly. I forgot how much they said to raise it at most per day. Let the calcium naturally fall into line.

Any reason why you are carbon dosing? If not stop that for the time being and get your parameters inline first then start the carbon dosing.

Also, try to get that Sg level back up. Have the ATO pump in salt water as it does it when the water level drops. That should help out but keep an eye on the Sg because it can go up quickly if not watched.

[xenon]

1.4 dkh every 24hrs is the recommended maximum dose when using recipe 1 (soda ash) because it raises the PH too high.

If you are using recipe 2 (sodium bicarbonate) you can rise it faster.

[Randy Holmes-Farley]

I'm not sure on that 1.4 dKH recommendation. Where did you see it?

Lots of people have low pH and so they can easily accomodate more. :)

[elaw62]

I'm sorry about being vague in what I was seeking. Yes Randy I need advice on best way to proceed. Right now I'm adding recipe #1 alk. part. I have a rk light controller & constantly have ph of 8.55 during the day dropping only to 8.35 at night. when I dosed #2 I believe it spiked ph enough to stress tank even though spike was short term so I started using #1. I think I have a grasp that the alkalinity of the tank is like a bank and is seperate from ph. the gradual tendancy of breaking down waste tends to gradually withdraw from the bank & if one allows the alkalinity to drop too low it could cause a rapid drop in ph. probably over simplified I know.
I fight a brown filamenteous algae that grows on the plastic overflow & return nozzles so I dose carbon. this has helped tremendously as I used to have this slimy brown junk all over my rocks before dosing and that has completely cleared up.
why does my ph remain high but dkh stays on the low side. test kit error?
I've been dosing approx. 1 cup alk. a day over the last couple of days to try & raise dkh. before that I was dosing 30 ml. every day. I have a 3 pump doser that I plan to bring on line after I figure the correct amount to maintain levels.

[bertoni]

pH at 8.55 isn't high to be a problem, but you might be seeing some testing error. I don't think the pH should get that high when dosing recipe 2. Does the tank have a skimmer?

[elaw62]

yes. tank has a euroreef skimmer, not sure of model but here's a pic. Also ph is monitored by neptune AC jr. looking at ph this morning before leaving for work registering 8.65. I run cheato on reverse light schedule from tank trying to keep it stable.
http://i1239.photobucket.com/albums/ff503/elaw62/IMG_1855.jpg

[bertoni]

That sounds like a measurement problem, unless the tank is getting kalk in some way.

[elaw62]

I was using kalk in the ATO. I have stopped at present.

[marke]

Recalibrate the ph probe

[shifty51008]

i would calibrate the pH probe. dosing Recipe #2 alk should lower the pH where Recipe #1 will raise it.

[elaw62]

i would calibrate the pH probe. dosing Recipe #2 alk should lower the pH where Recipe #1 will raise it.

my mistake I misstated earlier. I was dosing #1 & felt it was spiking ph so I began dosing #2. was wondering if there is a balanced alkalinity part such as mixing #1 & #2 where it would have minimal or no impact on ph.

[shifty51008]

i have heard 1/8 cup sodium carbonate (soda ash), and 1 cup sodium bicarbonate (straight baking soda) in 1 gallon of RO/DI water. will make the alk part with no impact on pH. may want someone like Randy confirm it though.

[Randy Holmes-Farley]

There are specific ratios which have no impact, but it depends a bit on what the pH is at which you want no impact. But the pH effect of sodium bicarbonate alone is very low, so just a bit (maybe 5-10%) of sodium carbonate balances it to no pH rise.

That said, most people can benefit from a boost, and I recommend the baked baking soda (carbonate) recipes for most people. :)