Extremely High pH

[Demosthine]

Hello Everyone.

Has anyone had any problems with really high pH levels? I set up a scrubber about four months ago and removed the rest of my mechanical filtration. Everything was going really well for about three months, registering zero for my Phosphates, Natrates, and Nitrates. My pH level is so high (9+) that it has killed all but my yellowtail damsel.

I thought the scrubber wasn't supposed to change the pH level very much, if at all. Prior to the scrubber, I was having to add dKh Buffer to maintain the higher levels, but now I can't get the levels down. I've had the scrubber lights off for about three weeks to see if that lowers it, but I need to check all of my levels tonight.

Hopefully someone has some good recommendations. I'd prefer not having to buy the CO2 or air pump to adjust them. That doesn't seem like a very realistic or good idea.

Thanks.
Scott

[SantaMonica]

Well it's not the scrubber doing it. At best you will get a 0.1 or 0.2 increase in pH.

For me, high pH comes from topping off with kalk water too fast.

[Demosthine]

Thanks for the prompt reply. What is kalk water, though? I'll look it up here in minute, but maybe you have a better explanation. And would adding the top off water quickly make that much of a different? I am adding the water quicker than I use to, but I'm not sure how that would correlate to the pH level.

Scott

[Amphiprion]

How much aeration do you have in your tank? Increasing (via protein skimming, water circulation) that should stabilize your pH a bit better. Kalk water = kalkwasser = lime water = a calcium hydroxide solution with a very high pH. What additives do you use? Any buffers?

[Amphiprion]

Something else I should've thought of sooner is whether or not your test is accurate. I'd suggest getting a second opinion. Also, what is your alkalinity? The carbonate/bicarbonate should be able to resist rises in pH better than that under many circumstances, unless there is significant input of a basic substance.

[rygh]

Technically, a lot of growing algae could pull a lot of CO2 out of the water, and really affect PH.
Good chart toward the end of this page.
http://www.csd.net/~cgadd/aqua/art_plant_co2chart.htm

Seems unlikely though. Since it really should naturally balance out, and take a LOT of algae.
(Algae needs CO2 to consume CO2, so how could it drop it that far)
Especially to 9.

Since it killed a fish, may not be a bad test kit.

Easy enough to test.
1) Turn the lights out on the ATS, see what happens to PH.
Without light, cannot use up CO2.
2) Blow through a straw into the tank for a while, see what happens to PH.
Should add a lot of CO2 to the tank.

[rygh]

BTW: Check your ammonia levels!
If something big died, it might overwhelm the ATS/bio filtering.
High ammonia can make some test kits think the PH is very high.

[Demosthine]

Thanks for the replies everyone. Let's see if I can manage to answer them all in order...

Amphiprion:
I have excellent circulation in the tank. I have a Cascade 1200 with the jet bar facing at an angle upwards so that the top of the tank has excellent oxygen exchange. I also have two water jets inside the tank circulating the water, though not actually "circulating" it in the true definition of the word. They basically face towards each other.

I am adding Kent Marine's Iron and Manganese, plus Magnesium, if I remembered right. I was adding a powdered calcium supplement (mixed into a one gallon container and then syphoning out the non-resididual). I've stopped adding the calcium because it wasn't working to raise the levels. I've never managed to get the calcium to register in the test for more than about 8 hours. I'll get to that in my "possible" solution.

I also had the test done at the LFS when the problem first started and then yesterday. Both confirmed my test results, so I know it is not a bad test.


RYGH:
I have two screens that are lit on only one side. Each screen is roughly 7"x10", so I don't think that is the problem. I've been running the system without the scrubber for the last month and have stopped adding the calcium supplements. The pH has gone down and is currently registering about 8.6.

I have been checking periodically and my ammonia, phosphates, nitrates and nitrites have continuing to register zero the entire time, so that doesn’t appear to be the problem, either. I do have some algae that has grown in the tank, which is probably why these contaminates are being eliminated.


Possible Solution:
I spoke in much more in detail with my guy at the LFS and he remembered I had purchased the Aragonite substrate. I didn’t realize it, but apparently the Aragonite breaks down and releases trace elements. As the tank was a fish only tank, the trace elements were not being consumed in adequate quantities. This resulted in excessively high concentrations of calcium and such, causing it to precipitate and fall to the bottom. With me adding the additional calcium, it made the situation much worse.

His recommended action is to do a 50% water change and replace the water with ocean water. This will help balance all of the elements from the start. He said to add a lawnmower blenny or equivalent to process the substrate and to add in corals that will consume these trace elements. Theoretically, based on the information he gave me, that will solve the problem. I’ll be heading down there right after work to pick up the blenny and a coral or two.

I’ve also restarted the scrubber, but at half-light. I’ll continue monitoring all of the levels and see where they go and how the tank recovers.

Thanks again for all of the help.
Scott

[rygh]

Big water change is always a good idea. Well, unless you just pour in tap water.
The aragonite/trace mineral idea... seems very odd.
(My LFS gives me nothing but bad advice, so I am very cynical nowadays)
Buying coral, or even more fish, when fish are dying seems like a bad idea. Especially if there is no calcium.

Zero calcium, and especially disappearing calcium sounds suspicious. Test dKH?

At any rate, seems like it is not the ATS.
A really great site for a lot of my non-ats problems/issues is http://www.wetwebmedia.com

[Demosthine]

I've been to a few LFS that had horrible advice, and to make their situation worse, their display and stock tanks were always dirty.

So far, all of the information Rick (LFS guy) has given me has been very sound advice. Nothing crazy or far out there in left field. The tank cycled exactly as he said and he has always been very honest about when to buy and when not to buy. Starting out, most of the stores I went to said to stock the tank almost immediately. He had me hold off and the tank cycled exactly as he said and was running well. My tank didn't do as well when I deviated away from his advice and switched from mechanical to the scrubber.

Anyway, the disappearing calcium doesn't sound as suspicious as one would think. When I started, I had read a few places that adding to much of a trace mineral will cause it to precipitate. I'm pretty sure that the last calcium container I had even said as much. And there has to be calcium in there because I have some coraline growing, primarily directly below my lunar light. With the tank lights off for the last three weeks and the levels falling back in line, I have a good coraline growth beneath the light.

The only fish that has survived all of my mistakes and trials was a yellowtail damsel. He is growing each month and seems to be really healthy and tough. I added two more yellowtails. I did just add the lawnmower blenny, but he was out of LPS.

We'll see how this all works out. I'm not buying anything expensive until things settle down.

[Demosthine]

Oh, and Rick had one of the most beautiful reef tanks I've seen so far. He moved to the Freshwater area, so he's not managing the reef tank anymore and it's not doing nearly as well. The corals aren't coming out as much, the substrate in all of the saltwater tanks has turned brown, and they can't keep the more delicate coral alive like he did. That's a great sign he actually knows what he's doing. He practices what he preaches.

[Amphiprion]

Possible Solution:
I spoke in much more in detail with my guy at the LFS and he remembered I had purchased the Aragonite substrate. I didn’t realize it, but apparently the Aragonite breaks down and releases trace elements. As the tank was a fish only tank, the trace elements were not being consumed in adequate quantities. This resulted in excessively high concentrations of calcium and such, causing it to precipitate and fall to the bottom. With me adding the additional calcium, it made the situation much worse.

His recommended action is to do a 50% water change and replace the water with ocean water. This will help balance all of the elements from the start. He said to add a lawnmower blenny or equivalent to process the substrate and to add in corals that will consume these trace elements. Theoretically, based on the information he gave me, that will solve the problem. I’ll be heading down there right after work to pick up the blenny and a coral or two.

I’ve also restarted the scrubber, but at half-light. I’ll continue monitoring all of the levels and see where they go and how the tank recovers.

Thanks again for all of the help.
Scott

One question you did not answer was how high your alkalinity was, along with calcium. Low alkalinity will not resist rises in pH very well. Higher calcium levels will prevent the dissolution of carbonate/bicarbonate.

I'm afraid I'll have to seriously doubt the aragonite theory. Aragonite is merely a form of calcium carbonate, and even with its better solubility, it is effectively insoluble in seawater, especially at the pH values you have now. Even if that weren't the case, your pH would have to be in the lower 7s to start the kind of reaction that is suggested. Bacterial acidic products can eventually dissolve calcium carbonate sands, but that doesn't happen quickly at all. Beyond that, bacterial films will quickly render most grains effectively insoluble, even further lessening the likelihood. Only calcium and carbonate products from the sand could cause your problem, though, not trace elements. It is just that what is described is very unlikely. If your values for calcium and alkalinity are truly high, I would first point to your salt mix. What kind are you using and how often are you changing the water?