Can't get PH up!

[Mugster]

Hi everyone. I seem to be having a problem getting my PH up to the 8.2 - 8.4 range. It seems to hover around 8.0 - 8.2, at night dropping as low as 7.8. I use RO water. I've tried using buffer but it still won't rise. I drip Kalk on a daily basis as part of the top-up. All of my param's are fine except the PH. Can anyone offer some insight as to why my PH is so low?

Thanks.

[titus]

Hello,

This topic has come up numerous times in the past and can be a result of many different issues. Bottom line is:
1) Good gas exchange
2) Water change

Quite often if dosing supplements doesn't help it means there's something out of parameter. So assuming your system is properly setup and without having to find out what exactly is the problem, water change would suffice. How often do you do that by the way?

[Mugster]

How much of a water change would you recommend? I change approx. 10-20 gals a week or thereabouts. BTW, I appreciate you taking the time to answer my questions.

Thanks

[Mugster]

I just finished making up 32 gals of water for a change later tonight. Hopefully this will help. Thanks for the advice. smile.gif

[titus]

Hello,

You do appear to be doing periodic water change. What is your tank size? Usually I say about 20% but different people have different opinions. Usually no need to do more than 50% unless I guess you dropped some copper in your tank and you need to get rid of it fast.

Since when have your pH begun to behave funny? But like I said, it could be gas exchange as well. Because I haven't been running my protein skimmer lately due to pump failure, my pH is also lower but there's no alarm here.

[Mugster]

Set Up Date :Nov 2001

Tank Size (LxHxW | Volume):180 gal(dual corner overflows)

Sump Size (LxHxW | Volume):55 gal(soon to have DSB)

Live Rock (Mass):approx. 180 lbs Fiji Prime

Live Sand (Mass):4"-5" fine arogonite

Lighting (Type | Wattage | Photoperiod):MH - 2 Iwasaki 250, 1 Iwasaki 400/VHO - 2 140w URI Actinic..1180 watts...11am-10pm (actinics first, then MH start at one end and come on at 30min intervals and shut off in same sequence, simulating sunrise and sunset).

Protein Skimmer (Brand | Model):DAS EX-1

Biological Filtration (Type):Bio Balls which are slowly being removed.

Chemical Filtration (Type):

Circulation (Rate | Brand | Model):4 MJ600, 3 Hagen402, 4 Hagen302 (PH's on timers running at intermintent intervals, off at night, on early morning).

Return Pump (Rate | Brand | Model):Mag12

pH (Morning | Evening):7.9-8.0 / 8.1-8.2

Temperature (Range | oC | oF):78 - 81

Specific Gravity / Salintity (g/g | ppt): 1.024

Alkalinity (meq/l | dKH):Have to test again, forget readings

Calcium (ppm):430

Ammonia (ppm):0

Nitrite (ppm):0

Nitrate (ppm):0.5

Phosphate (ppm):Not tested yet

Fish :2 Tomato Clowns, 2 Seabae Clowns (spawning biweekly), 3 Perculia Clowns, Yellow Eyed Tang, Flame Hawk, Fire Goby

Corals :Frog Spawn, Fox, Bubble, Leather, Green Star Polyp, Colt, Torch, Yellow Pagoda, Red and Green mushrooms, and 2 other frags that I forget the names of.

Invertebrates :Blue Leg, Scarlet, 2 Emerald, Turbo Grazers, 2 Reef Conchs, 2 Cleaner Shrimp, 2 Peppermint Shrimp, 2 Carpet Anenomes and 1 LTA (anenomes from previous 100 gal which have been doing great for more than 2 years now, size of dinner plates and hosts to the clowns).

Maintenance Program :Weekly 10 gal RO water change, Kalk dripped daily as part of top-up, weekly strontium 20ml, magnesium 40ml, and iodine 20ml dosing.

Additional Information (include estimated total system cost if known):Good coraline algae growth started. Some macro on LR which is growing well. Estimated cost 5-6k (probally higher once I gather all the receipts).

HTH smile.gif

[reefburnaby]

Hi,

I would be interested in your alk values. What ball park number do you think they are at ?

Also, how are you measuring your pH ? pH meter ? Test kits ?

BTW...have you ever kept Xenias in your system ?

Also, I noticed that you dose magnesium. May I ask why you are doing this ?

- Victor.

[ 21 March 2002, 09:56: Message edited by: reefburnaby ]

[Mugster]

Reefburnaby, I will test the alk tonight and post the results. As for testing the PH, I use a Pinpoint monitor. I've also used a test kit and it gave the same results. As for the Zenia, yes I have kept them before but wasn't successful due to poor lighting and water flow (first attempt at reefkeeping a couple of years ago). Why do you ask?

I'm dosing magnesium on the advice of a friend at my LFS. He's been in the business for 14 years now, has a beautiful display tank at the store and at home, so I figure he must know something. Mind you though, after all the reading I've been doing on here I'm starting to lean away from adding any supplements other than Kalk.

[reefburnaby]

Hi,

Excessive magnesium concentrations can cause the alk to drop and your pH to become unstable. The reason is because magnesium precipitates when magnesium ppm is too high and it brings the alk down along for the ride. Of course, your case isn't very servere since the magnesium isn't precipitating at a very fast rate (i.e. snow fall or calcium deposits on the glass). Without test kit for magnesium...it can lead to problems.

In the past (early 90s) magnesium ppm drop used to be a problem. This is because magnesium will slowly precipitate over time. However, new salt mixes have higher than normal magnesium levels to balance this effect. So, your friend may be correct in supplementing magnesium in the past, but it is no longer required today.

The reason why I am asking about the Xenia is because Xenia's actually don't do well with low pH tanks. It is just another indicator of low pH. In my experience, they grow like weeds in high pH tanks and very slowly in lower pH tanks.

I would take some of your tank water and put it in a bucket. Let it settle for a couple of hours and then measure the pH. This pH level is the pH of the tank water without CO2. If this level is higher than your usual measurements, then you probably have low water/air circulation.

I would also make a small batch of fresh salt water and measure that pH. If that pH is low...then well...you know what the problem is. Either the test kit is screwed or you have a bad mix.

Hope that helps.

- Victor.

[ 20 March 2002, 20:56: Message edited by: reefburnaby ]

[Mugster]

Thanks for the info and advice Victor, very much appreciated. I'm going to hold off for a while with the supplements and just drip Kalk. I think a couple of new test kits are in order too. I'm going to pick up some calibrating fluid tomorrow and recalibrate my PH monitor. My Zenia are doing great so maybe it's off a bit. I'll test tomorrow and post the results. Once again thanks.

Kev smile.gif

[TimT]

Hi,

A ph of 7.9 to 8.2 is a normal daily fluctuation on the reef. A ph of 7.8 is a little low. I would not recommend going as high as 8.4. You might want to check the ph of some of the make up salt mix as it could be on the low side. Also make sure you add the salt mix to the water and not water to salt mix.

Cheers,
Tim

[reefburnaby]

Hi,

Do you think you can fill out one of those tank specification forms on the main page of the board. This will provide us more info on your tank and it will help other see if there aren't any other potential problems.

Thanks.

- Victor.

[Mugster]

Tested the water last night and got a result of 2.2 alk. I did a 30 gal water change earlier in the day with only a slight rise in PH to 8.2. Good news is it didn't drop lower than 7.95 overnight. I have 2X20watt NO growlights on my sump which run 24/7.

[reefburnaby]

Hi,

Is that 2.2 dkH or meq/l ?

In any case, that is a bit low for dkH or meq/l. It should be around 8 to 12 dkH or 3 to 4 meq/l.

- Victor.