pH too high? What might be the cause?

[vaporize]

I hate my hagen test kit, it always tell me that my pH is 7.9 - 8.0, so I never pay too much attention until one of my friends have a pH problem recently.

After using a pinpoint pH meter (calibrated with 7.0 & 10.0 solution), it actually tell me that my pH is 8.50 when the lights are on and 8.45 when the lights are off for a few hours.

Now I kinda understand why my zoos and acan are not doing too well at all.

I am trying to find out why my pH can be so high? It is out of the safe range or 7.9-8.3 right?

It is in my 120G display tank, without Calcium reactor. The only thing that I can think of are different is that I might have:
- Kent Phoshpate absorber (I am thinking this is the cause of high pH)
- Marineland Activated Carbon
- lots of microbubbles (but this should decrease pH right?)

I do not add any Ca/Alk buffer or other additives at all. Feeding only using NLS pellets and tiger shrimps (for anemones).
__________________
Vaporize
120G, 200lb LR, Berlin Classic Hangon, 2x400W MH light + 2 NO Flourscent, tiger & zebra hermit, narississ & astea snails, some mushroom, zoo, brain, colt, 2 rose BTA, torch, frogspawn, birdsnest, merulina, blue & purple goniopora, ricordia, greenstar,clove, candycane, abalone, breeding pair ocellaris in green bta, blue tang, flame angel, blue angel, boxing/blood/peppermint shrimp etc...

[Danamck]

vaporize -

What salt are you using? Have you measured the PH of a newly mixed batch of water. I would start there.

Kent make 2 different Phosphate reducers: Phosphate Sponge (have not used, but have read negative reports) and Power Phos (have used - no effect on PH in my tank). I have also used Marineland activated carbon with no PH issues. Let's start at the beginning and check that water.

BTW - while 8.5 is a bit high for a reading when the lights are on, it's not that far out of line, IMO. I try and keep my tanks at 8.2 - 8.4.

[vaporize]

Thanks the salt mix I use is Instant Ocean

A few more data.

pH before lights are on pH 8.1
pH of tap water straight from tap 7.5
pH of salt mixed with RODI water 8.34

pH of RODI water 8.3 <--- I think this might be an issue, not sure why this high.

I think i am actually using the Kent phosphate sponge, can you tell me what bad things that has? It's phosphate & silica sponge I use.

Thanks for any insights

[fat walrus]

1) make sure that the probe of the pinpoint is clean and free of mineral build-up.

2) pin-point ph monitors tend to read high when battery is low.

[fat walrus]

Originally Posted by vaporize

pH of RODI water 8.3 <--- I think this might be an issue, not sure why this high.

that is impossible.
that is either NOT RODI water, or you measuring device is wrong.

[wwest]

do you have a RODI unit or do you buy it from a store?

[vaporize]

Okay Here's an update, after 1/2 hr RODI water drops back to 7.1, so I think the pinpoint probe is right.

So that ruled out, what else can incresae the pH?

I am thinking I added a Caribsea Reefbones base rock in, without much curling the rock, but I don't think those might cause high pH, any ideas?

[fat walrus]

Originally Posted by vaporize

Okay Here's an update, after 1/2 hr RODI water drops back to 7.1, so I think the pinpoint probe is right.

So that ruled out, what else can incresae the pH?

no, it not ruled out. RODI water cannot be 7.1 ph. i am purposly not telling you because i want YOU to look up the ph of RODI water.

[vaporize]

pH of pure water is 7.0, so what is the issue here?

I do not think it is related to the original problem at all.

[Amphibious]

If I may add my 2 cents worth here. I use a pinpoint PH monitor and my PH runs 8.2 in the am before lights on and as high as 8.5 before lights out in the evening. I don't consider 8.5 too high, on the high side yes but not too high. I have a couple of Zoa colonies growing like mad. Here's a pic of one from about two months ago.........



And the one below from a couple of days ago...........



You can clearly see they are open, healthy and growing. The PH is not doing them any harm. Sometimes Zoas take awhile to settle in and open up. I think you need to look at other things for the Zoas not opening. How long have you had them? How long has your tank been set-up?

Personally, I don't think your PH is too high. Relax and enjoy your tank.

[Amphibious]

I just reread your original post.

Originally Posted by Vaporize

I do not add any Ca/Alk buffer or other additives at all. Feeding only using NLS pellets and tiger shrimps (for anemones).

I would highly recommend that you change this habit to testing for Calcium, Alkalinity and Magnesium along with your PH. The four of them are intrinsically related.

You have some stony corals and other Calcium dependant critters in the tank. They are going to deplete available Calcium and then suffer when there isn't enough for proper growth. The low Calcium will throw of your Alk which will affect your PH and if you are not adding Magnesium it simply mucks up the whole Calc, Alk, PH balance. It's very important that you learn this and the sooner the better. We all put a lot of blood, sweat and money in our reefs. Our responsibility is to provide as good a home as possible, this is pretty basic husbandry.

[Danamck]

Good catch Amphibious. I completely agree. Vaporize - get out those test kits and report back the readings you get.