Another alk/pH question

[SaltyTX]

Hi all- New to this board.

Out of respect for other's problems I am starting a new thread even though it probalby overlaps several others.

A little about my tank- 26g, 20lbs LR, 3" sandbed, 2 powerheads totaling about 450-550 gph of flow 2x24 t5 lights. Inhabitants- 2x Occelaris clowns, 1 peppermint shrimp, 3 hermit crabs, 2 nassarius snails, pulsing xenia, yellow polyps, 2 small zoa colonies, a mystery coral (very small) and a sponge.

My issue- 7.7-7.8 pH with alkalinity of about 8dkH. Problem was, using IO salt, doing a water change (about half the volume) the dkH would be "normal" then within 24 hrs drop 4 points. The pH would of course drop as well. No amount of surface agitation helped the situation appreciably.

Went to LFS- sent me home with some Kent superbuffer. Now, the hardness is up to 12-13 dkH and the pH is right around 8.

Current stats-

78 degrees, 0 nitrates, nitrites and ammonia.
phosphate is high- about .8
pH about 8
hardness 12.5 dkh


So.......should I drop the superbuffer in the trash? give it some time? add some limewater? and if I add lime water, what is the best way?

Sorry for the novel, thanks for any answers or guidance.

Greg

 

[tdgates10]

Welcome to RF!

First, what kind of test kits are you using. I kinda went through the same thing you just experienced and of course it was all due to a bad test kit!

 

[SaltyTX]

Tetratest or whatever that laborett brand is. I should have purchased the API or something else, but hey, I had no idea, plus the kit worked well for me on my old tanks.

I have considered that theory as well, but for the fact that the LFS got the same results as me and the test kit is accurate when testing brand new IO salt, proper pH and alkalinity.

 

[DonW]

The buffer is of course raising your alk. Use it to keep alk up and something else to keep ca up. Dont worry about the ph. Ph issues are either high co2 in the room or excess nutrients in the tank. If the tank is clean then dont worry about the ph. You will cause more problems by trying to fix a ph problem with additives.

Don

 

[SaltyTX]

Of course one has to worry somewhat about pH. 7.7 is worry worthy- calcification does not work as well in an acidic environment.

If it was only fish, I would not need to worry as much, but with the corals, how could I not?

 

[DonW]

First you have to understand how you get to a ph of 7.7. It takes co2 and quite abit of it. This means your home is sealed real tight with too many people breathing or your tank is dirty. This assumes the test is accurate which I doubt. None of the above can be fixed with buffers without scewing alk as you alredy found out. The next option is to open up the house and clean the tank as needed.

Don

 

[SaltyTX]

The tank again, zero everything and a low bio load (as outlined above)

Define "dirty" I've seen it used, but dont quite get that. I mean, nutrient rich isnt a bad thing. If you mean decomposing organics it should not be the case as the nitrites/ites/ammonia are zeroed out.

The house is sealed well, but after 3 days of the windows open (we had beautiful weather this weekend) it made a very minimal difference.

Despite all the CO2 and dirty water theories- that does not explain the consumption of the alkalinity. I dont see how the test could be accurate one test, then not accurate the next, then back to accurate.

 

[DonW]

First its not really theory its fact. Decomposition consumes alk and reduces ph. You have three choices ambient co2, dirty tank or bad test kit. A test kit is not a good way to test ph when you trying to tell the difference between 7.7 7.8 or even 8.0 a well calibrated meter / probe is how you get accurate numbers.
I'm also assuming your not using a ca reactor.

Don

 

[Pentagona]

You don't neccessarily have to have nitrates/trites or ammonia to have organic decomp happening in your tank either. I run a really nutrient rich tank because of the way I feed, with no traces of NO2 NO3 etc., but I still fight pH ALK drops all of the time becuase just having a nutrient rich environment results in decomp. I keep up with more than your usual water change schedule to stay ahead of the nitrates and such. I have learned over the past couple of years what kind of dosing it requires in order for me to maintain optimal pH and ALK levels and still be able to feed the way I do.

 

[Pentagona]

I suspect that you may also have some other sort of chemical imbalance happening here to further exacerbate your problem. What are some of your other readings such as magnesium/calcium? What kind of sand bed do you use if any? fuge? no fuge? macro or niuscance in the display? With you Phosphates as high as they are, are you using RO/DI water or tap? Some more specifics about your tank may help lead to better concrete answers.

 

[SaltyTX]

no fuge, no real major algae problems, just a little will grow on the glass. There is a macro algae in the tank, but unsure of species. Grows in nice dark green hairy clumps attached to the rock. The crabs keep it trimmed

no calcium reactor.

no sump.

will get mg and ca tests this weekend to double check mg and ca levels. I've never had any problems maintaining parameters until now, so never got the test kits.

phosphate is 1.3 ppm from the water supply. not ro/di

water changes are about 20% weekly

deep sand bed (~3")

Penta- What do you dose in your tank, and how?

 

[jag3534]

OOH, that is HIGH phosphates in your water!! holy cow! Do you use a phos reducer? like phosban or anything? And your algae kinda sounds like green hair, which can consume a lot of nitrates, and give you a false reading on your test. we had that problem a while back, BIG problem.
Do you dose anything? what do you feed and how often?

 

[SaltyTX]

I dont think its the hairy algae, it looks similar to chaeto in texture. Maybe thats what it looks like though. It has not expanded its territory.

Yea, i know i gotta kick the phosphates down, is phosban a decent product to do that? The phosphate in the tank is lower about .6 to .8 still too high, but much lower than the supply water.

What about swapping to kalk for a pH booster? that makes phosphates precipitate out, right?

 

[jag3534]

I've heard a lot of people that use it and like it, but i've never personally used it, we got lucky here with our water. Another option is if you have any stores around you that sell rodi water, that could be good, because it's already balanced & mixed. I don't know if thats avail where you're at. ?? I wouldn't switch to kalk without testing the params first. Because if you od on calc, yoursytem can crash. and depending on where your calc #is at, if its higher than oh, 420 or so, it can start to drop your alk, and cause problems. I'd be very curious to know what your calc # is. and thats funky with the algae, i wonder what it is???

 

[kgross]

Do you have any surface agitation in your tank? With no sump it is possible to have high co2 levels in the tank itself to cause a depressed pH Do you have a protien skimmer on the tank?

But as Don has said a low pH is caused by low alk, or high co2 levels. Unless you are doing something very strange with your tank and dosing, those are the only things that can cause it.

Kim

 

[SaltyTX]

I have almost 600 GPH flow in the tank, much of which is directed upward at the surface to knock down the speed of the flow. I can aerate the tankwater outside and the pH goes up a little, but not enough.

I do know the tank "consumes" the alk, which makes me lose the buffering capabilities and the ability for the pH to stay up. This was the root of the question- how does alk disappear in 24/36 hrs?

I dosed the tank 2x with the super buffer (1 tsp/day.) The alk is up a bit too high now, and has yet to fall drastically like it did at first. I'm testing it every day to keep an eye on it and learn what is going on.

 

[Pentagona]

Salty, I use a Kalkreactor as my MAIN means of keeping my pH/ALK balanced, however, I also dose both Seachem Reef Complete and Reef Calcium (1/2 amounts each) in order to gain the benefits of both ionic calcium and calcium gluconate whenever I need to bump my calcium up. Occasionally I have to use a buffer as well as the Kalkwasser in my reactor becomes exhausted until I replace the media. Bare in mind though, that I've got a 240gal tank which changes the game a bit from a small set-up like yours. A couple of thoughts here though. Since you are sumpless I'm hoping that at the very least you're using a quality HOB protein skimmer. Secondly are you running open top or is your aquarium covered? As I'm sure you are aware gas exchange is crucial in removing excess CO2 from your system. If the aquarium is covered, it won't matter how many windows you have open in the house, you won't be ridding yourself of excess gas build-up in the tank.

If I had to venture a guess as to what might be happening, not knowing every detail of your set-up I would say that:

1) Your water supply pumping high phosphates into your tank, in addition to your tank being a high nutrient environment anyways (by your own admission) is feeding your hair algae.
2) Your hair algae (even if it may seem an insignifigant amount) is consuming any nitrates before they accumulate enough to register on your test kits.
3) The combination of organic decomp and natural production of CO2 by the algae simply photosynthesizing is creating a build up of CO2 in the tank.
4) An inadequate amount of gas exchange is occurring to rid the tank of said CO2 causing it to drive down your pH.
5) Low magnesium levels in the tank are inhibiting your ability to buffer ALK and further exacerbating your pH problem.

If you're going to run sumpless in a small tank, I would suggest (and I'm sure there are a lot of people who would disagree with me) keeping Magnesium levels high, as in the 1500ppm range. You will however need to keep a close eye on your calcium and ALK levels or you'll start to get sleepy snails This will probably help with the algae too and maximize your ability to buffer ALK. Then I would say find a way to vigorously aerate your tank water outside of the aquarium as you've said you have tried. It will take a while to release any excess CO2 so be patient with it. May take days to return to proper levels and proper oxygenation. Give those things a try for a week or so and see if everything returns to happyville. Lastly, a good water change in the mean time will help speed things along.

 

[SaltyTX]

Well thanks for the lovely post. Lots of info there.

I happened to get the Mg and Ca tests today......to add to the results

Mg is about 1500 (how about that..)

Ca 340, a bit low

retested alkalinity - 10.5


So. gotta bump that ca up and life will be more better

 

[Pentagona]

Salty, I missed the part where you stated you are running a 3 inch (probably deeper in some spots) sand bed. Do you stir your sand bed? Stirring once a week or sooner will help keep it from being a hot bed for decomp and CO2 production.

 

[kgross]

Saltytx.

If you have quite a few sps corals growing or lots of coralline algae growing you can have a loss of 2 dkh a day. Now if you don't have much for stony corals or coralline algae you should not be having that fast of a drop in alk.

Kim