High Alk, low PH?? How can I even this out?

ShawnSaucier · Mar 12, 2012

Good Morning everyone,
I have a new tank that has been set up for two months. It is a 75 gallon with a 20 gallon sump, skimmer is a Reef Octo 6", return is a Mag 9.5, 2 MP10 on reefcrest, and a Mag 7 for my bio-pellet reactor which also feeds into a reactor with carbon. I dose Brightwell A/B and a small amount of Kalk in my ATO. There is approx. 60lbs of BRS pukani/blue ridge/fuji dry rock for aquascape. I have two fish : small yellow tang and a royal gramma basslet with 3 peppermint shrimp. I feed them a combo of oyster egg, Rod's reef, mysis, and a seaweed blend once a day, which I add 3 drops of Brightwell amino to enrich. I have various frags and a small maxima from my last system. I use Reef Crystal salt with RO/DI water.
Readings are
Ph: 7.86- Salifert & Reef Keeper
Alk: 13 dkh- Salifert
CA 350- Red Sea
Ma: 1340- Red Sea
Trate:0- Salifert
Trite:0 - Salifert
PO4: 0.02-ish- Salifert
Sal.- 1.24 Hydrometer
I've been trying to get my parameters stable, but just having a heck of a time with it. I do a 10% water change a week/week and a half. I think part of the key is getting my Alk to drop. What can I do? corals are open and look "fine" but I know they would be great with a more stable water condition. What can I do??

VegasRick · Mar 12, 2012

Are you adding anything for alk? If so stop and let it drift down, if not then its the salt mix and don't worry about it. PH is a little low but nothing to worry much about. What time of day are you getting the ph readings? Low ph when the alk is above 8 is usually caused by co2. Try openeing a door or window. There are several threads here on dealing with low pH

REEFKEEPER10 · Mar 12, 2012

there is a couple of thing you can try but time might be all you need. it may balance itself out. you can use a Ph buffer for one to bring up the Ph. cut back on Kali is the other. it might work and if not it want hurt your tank. i had the same problem when i ran biopellets.

Reef Breeders · Mar 12, 2012

7.86 is just fine. My sytem has run with a max of about 8.1 for a year, no problems.

ShawnSaucier · Mar 12, 2012

Good Morning again everyone,
Thank you for the replies. I've been reading furiously since I posted. I don't want to make any rash decisions and over react, possibly causing a bigger problem.
I add 2 tsp of Kalk to 7 gallons of TO water a week, cleaning the bucket of any sludge with my weekly water change. Gonna keep an eye on it over the next few days
and see if it evens out a bit. A bir hard to open a window in this FL heat, but may just have too, or atleast at night. The PH has been pretty steady whether it's night or day,
and I tested the Alk after I posted this morning, lights still out, and it was at 15 dkh!.... will probably do a small WC today to hopefully bring it down a bit. I am not adding anything for
Alk, as questioned, but I was trying to boost my PH, CA and Mag up by double dosing the Brightwell though out the day?. Could this be the cause

CalmSeasQuest · Mar 12, 2012

2 tsp of Kalk in 7 gallons of ATO represents a tiny amount of Alk in a 95 gallon system and is likely not the source of your elevated Alk levels (especially considering your lower pH.) You must be adding Alk somewhere - RC with that tiny amount of Kalk would not provide for 15 dKh. I'm not familiar with Brightwell A/B, but it sounds like a 2-part additive, which if you are dosing both parts, will will increase both Ca and Alk. You can dose just the CA part without increasing Alk.

I would cease all dosing and allow your Alk to slowly drop on it's own and through water changes. Your low pH issue is probably a CO2 problem. If increased aeration is not possible, the Soda Lime CO2 scrubbers work very well and are inexpensive to deploy.

CJO · Mar 12, 2012

Reef Crystals salt is made with higher than NSW alkalinity. Adding to that your continued use of 2-part and only a few frags of coral is why you have high alkalinity. If I were you, I'd begin to taper off the use of 2-part until your frags get bigger.

When are you measuring your pH? If that is in the afternoon or evening, it would be a good idea to bring it up since it is likely dropping a bit at night. If that is your reading in the morning, I wouldn't worry too much about it since that is when your pH should be at its low point. If you want to raise it up, take VegasRick's suggestion on opening some windows to see if it's caused by CO2 buildup in your house. If that's the cause, there are various things you can do to bring it up- a refugium with chaeto, an airline to the outside, house plants, a CO2 scrubber, etc.

I would NOT recommend using a pH buffer to raise it.

CJ

ShawnSaucier · Mar 12, 2012

I love all of you guys,
another reason I love this site. Thank you again for your suggestions. Currently all of the doors on my stand are open with a very close window and patio door airing out the room. A beautiful cool morning here in Orlando. I should have realized that I was boosting Alk with trying to boost CA ,PH and Mag. As far as the PH it's been in the 7.8 range night and day according to the Reef Keeper and I've been testing during the daylight hours with the test kit. My Ca and Mag have been low and I have been trying to boost with the double dose on the A/B and Magnession additives for the last week. I did test the Alk today before the lights were on and that's where the 15dkh came up. Hopefully some morning air is going to help. Just trying to get the other parameters up to par, and unfortunately getting bad results on another end.