shrinking alkalinity.....high calcium

[kyles]

Randy, I got a bit of a problem.....my tank parameters are:

Ph 8.0 night and day -salifert
SG 1.025 (using Oceanic salt)
Nitrites -undetected -red sea
Nitrates -undetected -red sea
CA over 500 ppm - salifert
Alk 7.0 dkh -salifert

My tank has been set up for over 3 years now. 55 gal w/ about 25 gal fuge w/ DSB.
I drip Kalk (Balls pickling lime) every day/night.....about 3 tsp per gal. And it uses about 1/2 gal per day.
It is a mixed reef with mostly LPS, a few SPS, and now recently some soft (Xenia's Growing Like weeds)
My tank is covered but my fuge is always open with a fan circulating air in the stand.
No new live rock or anything other than Xenia
All my corals are growing good.


I do a partial H2O (ro/di) change every week, 4 gals, using Oceanic....used to use instant ocean.

I used to test my parameters every few days to a week and they were always so steady. CA 400, Alk 9.0, PH 8.0

Here is where it gets interesting......2 weeks ago I tested my parameters.... CA over 500, Alk 6.7, PH 8.0

So I tried to raise my Alk to about 10 dKH. 3 tsp of baking soda over 3 days (1 tsp per day).
I tested it on the third day about 1 hour after the last baking soda treatment..... CA over 500, Alk 10.2, PH 8.6 (sh..t)
Yes I was worried that the 1 tsp of baking soda caused such a spike in PH. I tested again, and again, same thing.
Then I tested the next day, and all was fine CA over 500, Alk 10.2, PH 8.0....Hurray!

Now here is where it gets weird,
I tested it again 5 days later and my readings were:
CA over 500, Alk 7.0, PH 8.0
My question is this, why is my Alk dropping so rapidly? And Why is my CA so high?
Am I adding too many tsp of kalk in my make up water, 3 tsp?
What is consuming my Alk so fast? and Not my CA.

[Sloth]

I'll take a stab -

When you say calcium over 500 mg/L, does that mean its off the chart? Where is it exactly? If its off the chart, it could be well over 500 and might actually be dropping at a normal rate.

IME - alk levels drop faster than calcium levels. Have you been adding any calcium chloride or anything other than kalk for calcium? Somehow, I think you need to stop adding as much calcium and concentrate on keeping your alkalinity up with baking soda. Once your calcium drops to a normal level, I think it will be even easier to keep your alk more stable.

[kyles]

yes, it's off the chart.
so then I should regularly add some baking soda? Is it safe to do so on a maitenance basis? What's causing my problem?

[kyles]

no, not adding anything other than kalk

[Sloth]

Too much calcium can be a very bad thing. Not sure why your calcium isnt dropping along with your alk. Maybe you just started out with high calcium from day one. Or maybe your high calcium is causing your alk to drop out of solution and precipitate on heaters and pumps.

I'd say stop adding kalk and let your calcium come down to normal levels (while using baking soda to keep alk stable). Once calcium is normal, re-evaluate what affect the kalk has on your tank. Test often. If it jumps back up, you might need to add less kalk and keep using baking soda to keep alk constant.

Whatever you do, don't add anything else that increases your calcium levels until you get an accurate reading. Just do whatever you can to get your levels normal and then go from there.

Adding baking soda on a regular basis will not harm your tank. I've been adding a teaspoon a day to my 25 gallon for a year. Just make sure you keep up with your regular water changes too.

[Sloth]

Come to think of it....
maybe I can't keep my own parameters stable because I've been using baking soda. Hehhe. Take my advice with a grain of salt. :)

The stuff is reef-safe even in the long run.. Thats for sure.

[Randy Holmes-Farley]

IME - alk levels drop faster than calcium levels

Yes, that's what should happen. A 20 ppm drop in calcium is balanced by a 1 meq/L (20 dKH) drop in alkalinity.

I'd get a real calcium measurement. Use a second syring, if necessary. Then add the results together.

Continue the limewater, and also add some baking soda, or baked baking soda since the pH is low. Dissolve it in some freshwater first. Add a teaspoon per day until the calciuum drops below 500 ppm.

It may be that the limewater is just not adequately meeting the demand, and so you need some additional supplements of some sort, or possibly more limewtaer if that is possible (or more lime plus vinegar).

[kyles]

I used to add the vinegar too, but I got some clumping in my DSB that I attributed to the vinegar. I actually read an article that says to dissolve the kalk in vinegar first, then add in the RO/DI water

[kyles]

Thanks Sloth and Randy.

It may be that the limewater is just not adequately meeting the demand, and so you need some additional supplements of some sort, or possibly more limewtaer if that is possible (or more lime plus vinegar).

Randy, Wouldn't more limewater make my calcium / alkalinity disparity even worse?

[Randy Holmes-Farley]

I actually read an article that says to dissolve the kalk in vinegar first, then add in the RO/DI water

Despite what some folks claim, the order of mixing of vinegar, lime, and water makes no difference.

Wouldn't more limewater make my calcium / alkalinity disparity even worse?

Disparity? You mean the high calcium? Limewater will supply both calcium and alkalinity in the same ratio that they are consumed. So once you reduce the calcium, if you then add enough of a balanced additive like limewater, you should be all set.

[kyles]

Limewater will supply both calcium and alkalinity in the same ratio that they are consumed. So once you reduce the calcium, if you then add enough of a balanced additive like limewater, you should be all set.

Well that's what I used to think, that limewater is balanced in alk and CA. And Limewater is ALL I have been adding for the past 2 years, but until recently, my alkalinity has been dropping fast, while my Ca is at the top of the chart.
What I'd like to know is what could be causing this? Will certain corals use a bunch of Alk? Do corals consume Alk & CA in the same ratio as limewater adds it? Is it Xenia, or Montipora......where is the Alk going?
Is it possible as sloth says ....
"Or maybe your high calcium is causing your alk to drop out of solution and precipitate on heaters and pumps
It would make some sense to me if because CA is so high, my alk just drops out.....hmmm, no wonder my hair algae has been growing again. Does Chaeto play a role in consuming alk too? I have some in my fuge..

[Hobster]

kyles,

In readin your thread, you stated:
"I do a partial H2O (ro/di) change every week, 4 gals, using Oceanic....used to use instant ocean"

When did you start using Oceanic? From what I have been reading it seems this salt is very high in Ca. Much higher than IO. When I tested my IO it was only around 300 or so in Ca and very low in Mg.

Just thought maybe this might have something to do with your high Ca and low ALk.

[Sloth]

nice catch, Hobster

[gtrestoration]

I have been using Oceanic and my calcium levels jump after and water change. 20 gallons in a 200 gallon system. Thats ok, but the alk is low, everytime I've tested it Salifert reads it at 2.5 meq/L. I push for over 3.25 or so. I now add 1 teaspoon baking soda and 1 teaspoon backed baking soda to the 20 gallon mixture. That takes the alk a little higher than the tank, but leaves the pH just about right.

Steve U

[Randy Holmes-Farley]

Well that's what I used to think, that limewater is balanced in alk and CA.

It is still true. :D

There are some things that cause slow drifts in calcium and alkalinity, but a quick drop in alk is not an indication of them.

I suspect that you are mostly seeing a math thing. If you start at 550 ppm calcium and 4 meq/L (11 dKH) alkalinity, you could drop all of the alkallinity (to zero dKH) via calcium carbonate precipitation, and the calcium would still be 470 ppm. Calcium just doesn't miove as rapidly.

Chaetomorpha has essentially no impact on alkalinity.

All corals as well as abiotic precipitation on heaters uses 20 ppm calcium for every 1 meq/L (2.8 dKH) of alkalinity (ignoring that some magnesium also gets into the CaCO3).

Water changes, the incorporation of magneisum and strontium, calcium and alkalinity in top off water and foods, and the nitrogen cycle can all slowly skew the normal values when using a balanced additivge, and ocassional corrections will be necessary.

[crpeck]

I would double check your Calcium with another test kit. I just bought a new Ca test kit from Salifert that is giving me between 50 - 100 more than it should using a reference solution. I've always had good luck with Salifert, but something is wrong here. When I test the reference solution using a Seachem test, I'm right on. I've done the Salifert 3 or 4 times on the reference solution to double check myself and its off by the same amount every time.

If you try a different Ca test, I'd be interested to hear what you get. I'm trying to figure out if I've got a bad Salifert batch or if I'm doing something wrong.

Good Luck!
Cathy

[datman422]

great thread, tagging along for I am in the same boat currently. :)

[cagri]

same has been happening to me since I switched to oceanic, it has high calcium 450+ and low alk, if I try to raise alk in the new make up water by more than 1mq/l by adding baking soda first then it snows(I guess because you can't have both high alk and calcium, one has to give), and then both calcium and alk drops.

It is difficult to maintain the balance with Ocenic(if you have alot of corals) because of its high calcium content. So I let the calcium slowly drop to 400 - 420ppm range while maintaining alk around 3 by adding baking soda and little kalk, and once I get there, I keep it at that level by adding more kalk.

[Randy Holmes-Farley]

Cathy:

If you try a different Ca test, I'd be interested to hear what you get. I'm trying to figure out if I've got a bad Salifert batch or if I'm doing something wrong.

I'd suggest asking Habib about this in the Salifert forum at RC. Perhaps the Salifert kit is off, you aren't using it quite right, or the standard is off.

Cagri:

e has been happening to me since I switched to oceanic, it has high calcium 450+ and low alk, if I try to raise alk in the new make up water by more than 1mq/l by adding baking soda first then it snows

How low is the alkalinity? Do you have an actual value for calcium in that batch? Adding 1 meq/l with actual baking soda should usually cause a problem. How much bakinng soda did you use and how did you add it?

[crpeck]

Thanks, Randy

After doing a search, I've found at least 3 other people posting about unusually high Ca with Salifert tests. Just checked out Habib's forum and there's 2 more saying they're getting higher readings off of their new Salifert kits than their old ones side by side.

I'll post over there and hopefully can get it figured out. I've double and triple checked myself and I'm sure I'm following the directions.

Thanks!
Cathy

[RQ]

I have the same problem with alk. I tried to rise it with baking soda, and obtained the same results as kyle. At first the alk rose and after a week returned to previous levels.
I m still searching for the solution.

[Randy Holmes-Farley]

At first the alk rose and after a week returned to previous levels.

Are you talking about in an aquarium, or a bucket of artificial salt water?

[cagri]

Randy,

I mixed 40 - 45 gallons of oceanic salt. Results were 480 ppm Calcium and 2.5 - 3mq/l alk at 35ppm salinity, so I decided to push the alk higher by adding kent's alk suplement(reef builder), I calculated that if I added 2 teaspoons it would raised the alk by 1 mq/l, when I did that it started snowing , and then all levels dropt. Calcium dropped to 350ppm, and alk was like 2.0 mq/l.

If I add the mixed oceanic salt with 480 calcium and 2.5 alk into my tank first , and then supplement it with alk for couple of days to maintain 2.5 - 3 level, and let the calcium drop to 400 - 420 level, and then supplement it with full power kalk mix, all is well.

I just found out that it is very difficult to maintain alk when calcium is very high ( > 450 ) with just kalk, once calcium drops to 400 level, it seems it is much easier to maintain both with just kalk.

In 3 month I will be upgrading to calc reactor, and will see how that will work out.

[kyles]

Wow, a lot going on in this thread.
I did check my Salifert CA & ALK test against a Red Sea....they were consistent......

On Saturday, before I did my water change My test showed:
PH 8.0
CA 500
ALK 6.7 dKH (after adding 1.5 tsp of Baking Soda w/ my 4 gal water change, it jumped to 10.9)

Okay, It's Moday morning, I just checked my readings again.....
PH 7.9
CA 490
ALK 6.1 dKH (after adding another 1 tsp of B. Soda it went to 7.8)

So in just 2 days, my alk droped from 10.9 to 6.1

So it appears the CA is coming down slowly but the ALk is droping very fast in just days, yet jumps at the slightest adjustment.

I think there may be something wrong with Oceanic salt, maybe a trace mineral that screws up your alk/Ca levels? Maybe too much magneisum and strontium?

Maybe I should switch back to IO?

[Sloth]

My tank drops alk almost as fast. I use IO. But then, I did add a lot of trace elements in the beginning. If there is a problem, I think we both have it. :)

[Hobster]

kyles,

Randys article:

http://www.advancedaquarist.com/issues/nov2002/chem.htm

shows the relationship. Appears you are in zone 4. (as was I :D )
It takes a while for the Ca to move in relation to the Alk.

[RQ]

Hi randy
about your question, i am talking about an aquarium, not a bucket of artificial see water. The one described in "current tanks".
I tried to rise alk adding baking soda but with the same results as Kyles. Not only my Kh returned to the previous levels but my Ca was 380 and after dosing b soda, dropped to 330 in three days. So i stopped to add baking soda and pointed toward Mg wich is my target now.
but i don t want to hijack the thread so i m going to sart a new one later .
Thank you

[Randy Holmes-Farley]

I tried to rise alk adding baking soda but with the same results as Kyles. Not only my Kh returned to the previous levels but my Ca was 380 and after dosing b soda, dropped to 330 in three days. So i stopped to add baking soda and pointed toward Mg wich is my target now.

Perhaps the tank organisms ae just using it as fast or faster than you are adding it?

[Randy Holmes-Farley]

Cagri:

so I decided to push the alk higher by adding kent's alk suplement(reef builder), I calculated that if I added 2 teaspoons it would raised the alk by 1 mq/l, when I did that it started snowing

You mean Kent Coral builder, or Sechem Reef Builder?

Adding Kent Coral Builder is different than adding baking soda, although not hugely different. Still, adding a lot at once is more likely to cause precipitation than is baking soda as it won't have the same pH reducing efffect as baking soda.

Do you know the pH of the mix before adding anything special? Some salt mixes have a very high pH that, if not brought down by aeration, will greatly increase the liklihood of precipitation of CaCO3, especially if you boost the alkalinity.

FWIW, I don't add anything to my salt mix (except water) prior to adding it to the tank.

[Randy Holmes-Farley]

klyes:

So it appears the CA is coming down slowly but the ALk is droping very fast in just days, yet jumps at the slightest adjustment.

Yes, that's exactly how it is supposed to be. Alkalinity whips around like a jet ski while calcium is more like a slow moving barge.

[kyles]

Randy,
Yes, that's exactly how it is supposed to be. Alkalinity whips around like a jet ski while calcium is more like a slow moving barge.
Well thank you for all your help, it appears thats the exact scenario my CA & ALK is doing.
I loose about 1-2 dkh per day even while adding about 1 tsp of b soda per day.
But finally my CA has dropped to about 440 ppm, and my
ALK was at about 8.0....PH at 8.1

I still think I'm going to switch back to IO, because I never had to deal with shrinking ALK and CA off the chart before. If anything, My kalkwasser kept both to acceptable levels, and once and a while I'd have to add just a bit of turbo CA.
I don't know, maybe I've just been adding (3) tsp of kalk per Gal was too much......I am going to use about 1 tsp and continue to monitor.

[Randy Holmes-Farley]

I use IO and haven't seen a good reason to switch to something else (although i certainly would with a good reason). :)

In normal calcification, the drop is 2.8 dKH of alkalinity (1 meq/L) for each 20 ppm of calcium.

[Sloth]

I hope I'm not repeating anything that was already asked, but -

If corals use calcium and carbonates in the ratio you just described,
would precipitation on heaters and pumps remove calcium and carbonates from the water in the same ratios?

Does that make sense?

[RQ]

Originally posted by Randy Holmes-Farley
I tried to rise alk adding baking soda but with the same results as Kyles. Not only my Kh returned to the previous levels but my Ca was 380 and after dosing b soda, dropped to 330 in three days. So i stopped to add baking soda and pointed toward Mg wich is my target now.

Perhaps the tank organisms ae just using it as fast or faster than you are adding it?

But if the Kh is consumed as fast by the organisms, how can you explain the sudden drop in Ca (from 380 to 330 in three days)?

[gtrestoration]

If corals use calcium and carbonates in the ratio you just described, would precipitation on heaters and pumps remove calcium and carbonates from the water in the same ratios?

I asked about 3 weeks ago and the answer was yes.

RQ,

From your profile you are dealing with a large volume of water.

To compare usage and additives... my system is 200 gallons.

I drip 3 gallons limewater daily.
Also needed daily to keep alk above 8.5 dKH and calcium above 400 is 650ml each of Randy's 2 part homemade supplement.

This seems like alot, but daily tests have confirmed the need.

I now use a LiterMiter lll to drip all three of these and the system is much more stable and I'm not freezing up my pumps so quickly. When I used the dose-by-hand method I could lock-up a pump in less than a month.

Steve U

[RQ]

gtrestoration:
I drip 2 gallons of limewater daily, and that is enough to keep Ca around 400. The problem i have is with alk because is very low now (between 4 and 5 dkh). When i try to rise it with baking soda, the Kh return to the previous levels after a few days and the Ca make a big drop. After that I continue adding limewater as usual and the Ca come back to 400 after a few days but de kh remain as low as before.

[Sloth]

I think your tank is just using a lot of Ca and a ton of alk. The alk is getting used as fast as you can replace it. Its "idling" down at the point were your corals are no longer able to suck it out of the water to use with calcium to form calcium carbonate skeletons.
That's my 2 cents

[gtrestoration]

RQ,

So that I understand.

How many gallons of water does this system hold?

When you have added baking soda in the past...
How much did you add?
How did you add it, as in mixed with fresh water, and where did you dump it, about how much water?
What is the pH of the system, high and low ranges.

What is the dKH you would like to maintain?

Steve U

[Randy Holmes-Farley]

If corals use calcium and carbonates in the ratio you just described,
would precipitation on heaters and pumps remove calcium and carbonates from the water in the same ratios?

Does that make sense?

Yes it makes sense, and yes, the ratio is the same. The only small differences have to do with the amount of magnesium and other ions that get into the calcium carbonate in place of either calcium or carbonate, which varuous between corals and between corals and abiotic precipitation.

[Randy Holmes-Farley]

But if the Kh is consumed as fast by the organisms, how can you explain the sudden drop in Ca (from 380 to 330 in three days)?

If the alkalinity dropped by2.5 meq/L (7 dKH), or you added enough baking soda to balance that, or a combiantion therof, that would be exactly right.

Sudden drops in calcium in the absence of any alkalinity supplements or alkalinity drop are either the result of testing error, or water changes with a salt mix with lower calcium.

[kyles]

RQ,
In plain english, If you add any ALK supplement (B. Soda) then CA will ALWAYS drop.
If you Add ank CA supplement (Turbo CA) then ALK will ALWAYS drop.
The only time they won't drop is if you add a BALANCED additive.
I know it's weird sounding but that's how it is. And that's why we are always dosing balanced additives like KALKWASSER.
My problem is I get lost in the mix of things when I am adding balance additives, and one or the other drops.
If I were you, trying to raise ALK and not lower CA, is to add I would add some Turbo Calcium at the same time that you add your B. soda, that way you keep your CA from droping.

With 500 Gals, You might try adding 6 tsp of B.soda with 3 tsp of Turbo CA, keep dripping kalkwasser, and check parameters the next day and dose again if need be.

[kyles]

How much Kalk to you all use per Gallon of water?
I was using 3 tsp per gal, and dripping 1/2 g per day.

[Randy Holmes-Farley]

If you add any ALK supplement (B. Soda) then CA will ALWAYS drop.


It will always eventually drop when the alkalinity is used up in calcification. Some folks might interpret that sentence to mean that it drops right away, which it may not always do.

[RQ]

Thank you all for your comments. I will try to answer each one of them.
Sloth:
i didn t see any special gowth in my hard corals skeletons on the time (between three days and a week) were the KH is consumed, and when i stop to add baking soda, the system is in balance at KH 4,5 and Ca 400. Because of that, i suspect that the problem is not related with coral using the alk but with some chemical reaction in the water.
gtrestoration:
The total volume of my system (two tanks plus sump) is 486 Us gallons, but i have a DSB with a plenum and several pounds of live rock so i would say that i have a water volume of 330 g.

I will give you a practical example of what is happen to my siystem:
june 5: Kh 4 - Ca 390 + 3 tbsp of baking soda mixed in 1/2 g of RODI fresh water and dumped in a strong current along the day.
June 5 end of the day readings: Kh 5 - Ca 380
june 6: Kh 4 + 3 tbsp more of baking soda.
june 7: Kh 5 - Ca 330
At this point, because of the low Ca i stopped to add b soda, and continued with the normal use of limewater.
june 11: Kh 4 - Ca 375.

The ph is 8,08 /8,14

My dream is 7 dkh but with 6 i will be extremly happy.

Randy: I tested Ca with salifert kit (i have two of them and the old messure like the new one), and Kh with salifert Kit and Sera Kit and they messure the same, so i don t think i have a testing problem, and i didn t change water during the example given above.

Kyles:
As far as i know, not always the Ca drop when you add baking soda. And certainly not at the ratio that dropped in the example i given above. But i m intrested in the solution that you propouse (add baking soda and Ca in a bigger proportion ). i would like to know the opinion of Randy about it.

[gtrestoration]

RQ,

It will take about 6 tsp to raise your 330 USG by 1 dKH. Your system can easily use that much dKH or more in one day.

If your system is using 2.8 dKH per day then it shoud also require 20ppm calcium be added. That would require about 16 tsp baking soda for dKH and 13 tsp calcium chloride for calcium.

Non of these figures are considering the limewater you are adding. I dose the same amount year round even though the evaporation changes. This way I need not adjust anything other than RO/DI makeup water.

What I did to resolve the usage issue on my system was to put together a log sheet and tested each twice per day for 3 weeks.

I logged
• Time
• pH
• dKH
• Number of tsp baking soda added
• Calcium ppm
• Number of teaspoons calcium Chloride added

I was rather surprised at the amount necessary twice daily. I took the results of those test and averaged the daily amount needed. Now I dose that average daily, and test weekly.

My estimates of the needed baking soda and calcium chloride come from...
http://www.kademani.com/reefchem.htm

Hope this helps.

Randy,
Hope I'm not out of line in your forum.

Steve U

[Randy Holmes-Farley]

Thanks, Steve, :)

And certainly not at the ratio that dropped in the example i given above.

I think that you are overinterpreting noise in the test kits. You dosed only alkalinity supplements, and the calcium declined. That's normal.

Then you added limewater and say calcium rose, but not alkalinity. That doesn't happen. Perhaps the 330 ppm calcium reading was wrong, and the value was just steadily dropping from about 390 ppm to 375 ppm calcium.

IMO, you do need to add more calcium and alkalinity supplements. My suggestion is to use some sort of balanced additive system so you need not worry about such changes on a day to day basis. These would include limewater, the two part systems, a CaCO3/CO2 reactor, etc.

[RQ]

Steve:
IThank you for your advice and for the link. Both very usefull.
Randy:
I apologize myself because i didn t explain the procedure well.
I never stopped to add limewater during the example given above. In this case you conclusions are the same?
Anyway i really appreciate your help. It is a real privilege for me to be able to communicate with someone with real knowledge in this area of our hobby.

[Randy Holmes-Farley]

I never stopped to add limewater during the example given above. In this case you conclusions are the same?

You never stopped adding it, or you never added it?

In any case, if you didn't add any calcium only supplements (like calcium chloride) or a mineral acid (like muriatic acid = hydrochloric acid) then the calcium cannot rise from 330 ppm to 375 ppm with no rise in alkalinity. If you used limewater for that rise, the alkalinity would jump by 2.25 meq/l (about 6.3 dKH).

Anyway i really appreciate your help.

You're welcome. That's what this forum is for! :)

[RQ]

Randy:
I never stopped adding limewater, and i didn t add any calcium only supplement or a mineral acid, but the calcium rose from 330 to 375 with no rise in alkalinity (on the contrary, the alk dropped). This is exactly my problem. i can t rise alk. without a drop in Ca levels, and when i reached the 400 Ca by the effects of limewater the alk returned to 4 dkh.
Could be any other cause for this, than a noise in the test kits?
Maybe some kind of acid from de DSB causing precipitation of alk?

[Randy Holmes-Farley]

I never stopped adding limewater, and i didn t add any calcium only supplement or a mineral acid, but the calcium rose from 330 to 375 with no rise in alkalinity (on the contrary, the alk dropped).

Then that is a measurement error, not a "'problem". There is no mechanism for that to happen that rapidly in the absence of calcium or acid additions (or a water change with off spec water).

[RQ]

OK.
Thank you again Randy. I´m going to buy new tests and going to repeat de experience.
i will keep you informed in a new thread.

[Randy Holmes-Farley]

:thumbsup:

You're welcome.

[Pmesyngier]

Hi Randy , I know the RQ`aquarium and I think that problems are :
A)the sand bed is liberating H2S to aquarium water
b) RQ do not make water changes since a few years
c) The big algal grown (Caulerpa and Halimeda) is dropping ALk and Ca levels
d) RQ is ONLY adding kalk and MgCl2 . 6H2O to a 2000Liter reef tank (500gal aprox)
E) The reef have a great coral and coraline algal grown since 3-4 years
F) RQ use so little actived carbon and remove it once a month
For all these I think that aquarium water is "saturated" or deficient in cations and /or anions

[Randy Holmes-Farley]

For all these I think that aquarium water is "saturated" or deficient in cations and /or anions

I'm not sure what that means. Deficient in what?

the sand bed is liberating H2S to aquarium water


Why do you think that, and what do you think it is doing once released?

[Pmesyngier]

I'm not sure what that means. Deficient in what?

Deficient in carbonates and bicarbonates (and other anions or cations wich could interact with KH and Ca++) and "saturated " in cloride and organics compounds

Why do you think that, and what do you think it is doing once released?


I think that the problems in the sand bed ( too much organic matter in anaerobics conditions) could be creating H2S , and this could be neutralizing basics, downing pH and KH.

[Randy Holmes-Farley]

There is almost no chance, IMO, theat there is enough H2S released to impact alkalinity or pH. It is very toxic and small amounts could be a problem in other ways, but not enough to impact these much higher level chemicals.

Seawater is never saturated in chloride, and not likely in organics either, although the levels in an aquarium could be much higher than usual for seawater. c

Carbonate and bicarbonate are directly measured by alkalinity (dKH). So if those levels are normal, then the water is not deficient in carbonate or bicarbonate.

[Pmesyngier]

so , you think that there aren`t relation bettwen the sand bed and the " ph -kh -Ca dropping"?

[Randy Holmes-Farley]

No, I don't. :)

[Sloth]

Hey guys, I recently sold off 90% of my SPS and clams in my nano. I had a 24 hour alk drop of 3 dkh. Now my 24 hour alk drop is closer to 1 dkh. The tank was pretty packed with stoneys. Now I have a couple colonies and a few frags. I thought for a long time that something was severly wrong with my tank, but I'm thinking now that it actually was all the stoney corals using it up.

For what that's worth...

[Randy Holmes-Farley]

but I'm thinking now that it actually was all the stoney corals using it up.


:thumbsup:

The smaller a tank is, the more likely that is to be a problem too, since smaller tanks have more corals per unit of water volume, typically.

[Pmesyngier]

Thanks RAndy!

[Randy Holmes-Farley]

You're welcome. :)