how to control pH

[Booboo33062]

I have been cycling my tank. I put the cured LR in on 2-11th and I put the lights up on 2-16th.
Before I added it the water test showed:
pH 7.9 Amonia 0 Nitrite 0 Nitrates 10
The day after Amonia .25 Nitrite .25 pH 7.9 Nitrate 40
On the 21st I did a W/C after more water test
On the 22nd before I went to bed I tested just the Amonia 0 and Nitrate 0
I thought okay we're done the water was yellow in the tube with no orange. Woooohooo I thought.
Then on the 23rd in the morning I tested everything and got
pH 7.9 Amonia 0 Nitrite 0 Nitrate 15

How can I get the pH to stay at 8.0 or 8.1? It seems to go from 8.1 and 7.9
What happened to that testing? Do you think I just did the test wrong on the 22nd or by doing a W/C I stirred up the sand and caused another cycle to start over? I know it is still a new new new tank, and I was going to wait another 2 weeks or so. I was going to make sure it was stable.
Also one of my turbos died 3 days ago. It kind of shrunk up and I pulled it out. I hope I don't loose any more.
Thanks,

[Mike O'Brien]

The organic acid's produced from the curing rock will diminish the buffering capacity of the water, and the ph drop's with it. Maintain the alkalinity to keep the ph up.

[Booboo33062]

How do I do that? I am new to this. Is that where Kalwiser is used?
Sorry for the spelling.

[tdwyatt]

you need to give us a span of a day's worth of pH readngs, coupled to whawt your alkalinity and calcium values are at the same time. These values are so closely interlinked that not knowing the numbers for all makes a single pH reading meaningless.

We need to know;

• What are your values for 8am, 12noon, 4pm and 8pm pH, as well as your calcium and alkalinity, and your salinity for the system?
• Are you doing any supplementation for calcium and alk at this point?
• What is your photoperiod like?
• Do you have a sump or refugium, and if so, is it lighted on the same schedule for the tank, or dark all the time?
• How many macroalgae do you have in the tank, and how extensive is your coralline coverage now?
• Do you have covers on the tank?
• Does your skimmer have an outside source for air?

Inquiring minds wanna know!

[Booboo33062]

I'll have to get the calcium and alkalinity test then I'll post it. It may take me awhile to get them. I didn't know I needed them yet. Oh no!!!!

[Booboo33062]

Are you doing any supplementation for calcium and alk at this point?

No

What is your photoperiod like?
I have moonlights 24/7, Actintics 8 hours, Daylights 6 hours.

Do you have a sump or refugium, and if so, is it lighted on the same schedule for the tank, or dark all the time?

A sump under the tank with no light.

How many macroalgae do you have in the tank, and how extensive is your coralline coverage now?

The 50# LR I have has a moderate amount of pretty color. I don't know what you mean by macroalgae?

Do you have covers on the tank?

No I used to have a canopy, but we took the top off of the canopy and just left the botton half of the canopy so the fans fit since they are on the end.

Does your skimmer have an outside source for air?

I have a geoff DIY skimmer that is setting next to the tank stand.

[tdwyatt]

Originally Posted by Booboo33062

No

You will probably find that your alkalinity is quite low for ASW even in a tank without any hermatypic corals (ones that use up alkalinity and calcium to make skeletons that form reefs). Alkalinity is often consumed in relatively new tanks as a result of both sudden increases in biofiltration as well as decomposition processes for the dieoff brought in on new live rock. With the loss of alkalinity to sub-normal ranges, pH will shift into lower parameter ranges as there is nothing to counteract the abundance of CO2 dissolving into the water column from the air above the tank. CO2 is what causes the pH to drop in the tank as it hydrates and forms carbonic acid, and without any countermeasures from a proper bicarbonate/carbonate buffer system, the pH for a daily swing will be in the ranges you've listed, getting worse over time.

Originally Posted by Booboo33062

I have moonlights 24/7, Actintics 8 hours, Daylights 6 hours.

This is important to know because it will affect how long the photoautotrophs (organisms in the tank that use light to make food from CO2 and water usually, and usually in the presence of chlorophyll or some other accessory pigment for photosynthesis) will absorb CO2. This is related because the more photosynthesis that occurs, the more CO2 that will be taken up during the day, driving up the pH as the CO2 pool shrinks. Short photopeiods have short assimilation periods for CO2, so pH will tend to favor acidic conditions in takes set up so.

Originally Posted by Booboo33062

A sump under the tank with no light.

Some systems set up with short photoperiods can use reverse photoperiods in a refugium to help stabilize pH swings from night to day, but they usually must be on 24/7 to really do any good for this particular purpose, as during dark periods, photoautotrophs become net CO2 producers as they respire the carbonhdyates thay have made during the day for energy to perform maintenance, etc in these plants, algae, zooxanthallae, etc.

Originally Posted by Booboo33062

The 50# LR I have has a moderate amount of pretty color. I don't know what you mean by macroalgae...

Macroalgae are fleshy plant-like forms of algae that live in the ocean. They are not vascular like terrestrial plants are, and will come in many forms (red, brown, green, etc depending on their photosynthetic pigments). Knowing that you have a large or small algal population (including the red algae known as corraline algae) will help determine how significant a short or long photoperiod would be in such a system.

Originally Posted by Booboo33062

No, I used to have a canopy, but we took the top off of the canopy and just left the botton half of the canopy so the fans fit since they are on the end.

The canopy may have been an issue, but since you've removed it, prolly not now. Anything that traps CO2 on top of the water column is a problem with keeping a decent pH level, as it provides a means for CO2 to concentrate in the water as the concentration above the water rises. CO2 is very readily absorbed through the water/air interface, nd the higher the concentraion of CO2 in the air, the higher the concentration of CO2 will be in the water (pCO2, the partial pressure of a gas (here, CO2) in the water, like a percentage composition... sort of ). If you have a tight fitting hood, make sure it has good circulation to prevent both heat and CO2 accumulation.

Originally Posted by Booboo33062

I have a geoff DIY skimmer that is setting next to the tank stand.

I assume this means no, fit a flexible plastic hose to the intake for the air for the skimmer, and run it to an outside source of air for the skimmer to take in. Doing this will remove the recirculation of in-house air into the water column, bringing in outside air for the skimmer to make foam wuth. This reduces the chance that the air being used for foam formation is high in CO2. As the skimmer has a HUGE amount of surface area in the bubbles, it can introduce a large amount of dissolved gasses into the tankwater in a short time, so using outdoor air is cheap insurance that the CO2 level will not be a direct reflection of high CO2 content indoor air, which would drive overall pH down.


Almost all the things listed so far are means of limiting import of CO2 and improving export. Having an appropriate buffer level (alkalinity) is quite important in balancing the effects of ph introduced by high CO2 concentrations, specially in systems where CO2 accumuation is a problem (most homes, especialy in winter). Read through the post, get your test data back, and ask again with the rest of the information in hand!

HTH

[Phishnoob]

So will water changes every week add enough to offset for the CO2 without additives? Now I am getting worried.

[dobejazz]

BooBoo Excellent post Thank you! I am having the same problems low alk/ph and high Calcium. Very interested in your test results and the suggested fix

[tdwyatt]

Perry, it will depend on how your system is set up (DSB Vs. BB, how much rock, sump and substrates, etc. ) as well as how many corals and other calcium consumers are in your tank. A tank of most ly softies would use much less Ca++ than a tank of Stonies and clams obviously, but if you had a tank of soft Octocorals and all the rock was covered with purple coralline algae, your system may still be sucking up a ton of Calcium and alkalinity on a daily basis, enough to potentially stump growth of even octocorals if Ca++ and Alkalinity are not followed on a regular (weekly) basis for evaluation. This does not address issues with organic acids that would be byproducts of decomposition in the tank (detritus missed during siphoning or tht fail to be skimmed out of the system for example). In addition, high percentage coverage on the rocks by Corallinaceae will consume lage amounts of alkalinity to create the encrustations, and bicarbonate is one of the preferred sources (indirectly) for inorganic carbon by marine algae, so this makes it a doubled consideration for consumption of alkalinity in a closed system.


I would imagine that a weekly 10% water change will, if nothing else, provide a weekly bolus of alkalinity needed by the corals and other biotic alkalinity consumers, but again, it all goes back to who is using how much of what elements present in the system, and growth of organisms dependent on these elements may be limited by the absense of appropriate amounts of these hermatypic substances. Tanks with DSB aragonite beds may experience some dissolution of the sand bed, but this is often quite slow. Although it might be enough in a tank with a 15 cm DSB with low consumption of calcium and alkalinity by tank inhabitants, issues with biofilm formation over the granules, inadequate (inadequately low) pH to dissolve the aragonite, and low percolation rates for interstitial water through the sand are some of the issues that will limit the usefulness of this as a significant source of calcium and alkalinity.

Short answer: Test to evaluate alkalinity just prior to WC to make sure there are not problems.


HTH

[tdwyatt]

Kelli: What are your water parameters at this pint, specifically: Ca, Alk, Mg, salinity, daily pH swing, photoperiod, WC percentage and schedule, and how do you supplement for calcium and alkalinity currently?

[dobejazz]

I knew you would get me Tom!! I had great plans on testing and posting the results last night but Violets fever has pushed that back to tonite (hopefully) PH moniter on the 24 runs from 7.6 over night to 8.1 during the day. Calcuim was about 490 last week and I can't remember alk from last weeks test but it was low I am using salifert Calcium and Alk tests. I will run the tests again tonite and post the results

[tdwyatt]

Kelli, run one of the borax tests* on your probe so we can have a good idea about your calibration at this point. No point chasing our tails if we discover the issue is the probe (very common)...






*1/2 level tsp borax (sodium metaborate) dissolved well in 2 cups RO/DI or distilled water, insert the probe and let it stand for about 5 minutes with occasional swirling of the probe in the solution. Should read 9.18 +0.02 pH units for displays that read to the hundredths if the calibration is spot on, the probe is clean of biofilms and ca deposits, and the meter and probe are functioning correctly.

[dobejazz]

Ok tom will do. It is a brand new unit though and we calibrated it to 7 and 4 per the directions before we started using it last week.

[Doug1]

With it being winter, typically most houses will see raised CO2 levels, while not problematic to the people in the house, it can easily lead to pH decline in tanks as tom noted, esp if you have a large tank/sump surface with vigorous air/water turbulence or pump large volumes of CO2 enriched air thru skimmer