High phosphates and nitrates

Cindy,

Just a question, do you have a lot of green algae in the tank? Also do you have good growth of coraline algae?

Lastly, how well is the skimmer working. as in how often do you have to empty the cup?

John

 

Cindy

Also what was the previous records of the Alk levels?

I think what you willl find is the Alkalinity has dropped from what it was previously and that have allowed the release of Phosphates that are bound into the Calcium Carbonate that covers the grains in your sand bed and also on the rocks and other places.

I suggest you raise your Alk to at least 14dKH, run a phos sponge for a few days while maintaining the Alk/ Calc ratio and see if that helps

John

 

John could you please explain why you would have the Alk reading at 14 for us?

The amount of fish you can have. 120 gallon tank is really lower in gallon size once you minus the glass thickness and sand volume and then rock volume.

Your tank is really around 90 to 95 gallons.
So 90 divided by 5 = 18 one inch fish max give or take a few inches here.

The bio load is so heavy that water changes would be needed often, As you saw the Nitrates fall to almost half now but they will creep back up soon I believe.

Test before you do the next water change and about 2 hours after the water change. This is just diluting the problem so we need to find out what is causing the issue still.

You can use your turkey baster for the sand test.

Your cal and alk are a tad high but they will drop if you don't add anything more to the tank.
DKH should be 7 to 11 IMO.
Was your pH test in the morning or evening?

Try Matt's suggestion about stirring the sand bed alittle and vacuuming it up if this is possible on the next water change.

A bigger Fuge would help a little.

What brand of charcoal are you using again?

Thanks
Dave

 

Dave, I agree.  The calcium reading is high for sure.  Considering natural sea water at 35ppt salinity (1.0255 S.G. = 1.0265 with a refract) has a calcium level of  approx 415-420 ppm.  So at 1.023 S.G = 30ppt salinity....Balanced Calcium would be in the 353 ppm range (30ppt is ~15% less than 35ppt, from there you take 15% less than 415ppm).  Important thing to note, the same calcium is available to corals at a concentration of 415 as it is at 490.  If you think of salinity as a bowl, the larger the bowl (higher the salinity) the more calcium/alk/mag it can hold.

Personally, I wouldn't start worrying about your chemistry and playing around with it until you get your nitrates and phosphates under control.  I'm wondering if you are in constant mini-cycles with all the fish.  Even though your ammonia is testing zero, it may be getting broken down quick enough, but might be present for a short span (thinking of the lost fish).

Here is an article (which you may have read) regarding Reef Aquarium Water Parameters by Randy Holmes-Farley.

 

Nikki,
I am wondering why you are posting this? Just trying to understand what you are relating this to here.
By leaving the alk and Cal alone and doing nothing it will drop all by it’s self when pertaining to Cindy’s tank.

I don’t believe anyone is suggesting to change the chemistry at all,
Was suggesting ways to get nitrates and phosphates down as this is also part of the water chemistry and is the first thing needing dealt with. The only way to remove Nitrates is by water changes and this is what I suggested along with some other people.
Depending on what charcoal is being used this could also be a source for phosphates. ie: Mojoreef explains this well and is in a thread here somewhere.
John was suggesting an alk reading of 14 and I was wondering why he wanted this. Referring back to RHF saying 7 to 11 DKH range is best.

So can you give me some further details on the salinity information you provided and how that is related to Cindy’s tank I would interested to see what your meaning would be. Just being curious.

Thanks
Dave

 

Oh gosh! Sorry - I am being misunderstood. My comment about not messing with tank chemistry was regarding the alk raising comment posted by John. I do feel that the calcium is too high and am afraid of the tank being ionically unbalanced. That was where my point explaining the salinity was coming from.....to show where calcium levels are in conjunction with a certain salinity. By all means we are addressing the chemistry of phosphates and nitrates (apologies again for the misunderstanding). So basically the salinity comment was a FYI.

I'll see if I can track down some info on the charcoal, as I agree this could also be a source of phosphates, too.

 

No problem I was just wanting to understand you.

 

Dave, the reason is in the rest of my post, but maybe I didn't make it very clear.

I think the Alk is low in relationship to the Calc reading. Others have suggested leaving the system alone until the Calc reduces but I feel this will not happen easily because of the imbalance and I think it would be better to actually raise the Alk instead. By doing it this way you may not get the reabsorbtion of the Calcium deposits which I think have bonded phosphates. My 'theory', apart from other issues, is that there are large amounts of phosphates bonded into the calcium deposits on the rocks and in the sand. A drop in the Alkalinity ( at such a high Calc level ) is causing these 'old' deposits to reabsorb and therefore release the phosphates back into the water column.

That is why I suggested raising the Alk and also using a phos remover of some kind. It also explains why the previous owner didn't have the problem.



John

 

[quote author=JohnO link=board=Newbie;num=1086480105;start=15#27 date=06/08/04 at 15:08:51]

Dave, the reason is in the rest of my post, but maybe I didn't make it very clear.

I think the Alk is low in relationship to the Calc reading.  Others have suggested leaving the system alone until the Calc reduces but I feel this will not happen easily because of the imbalance and I think it would be better to actually raise the Alk instead.  By doing it this way you may not get the reabsorbtion of the Calcium deposits which I think have bonded phosphates. My 'theory', apart from other issues, is that there are large amounts of phosphates bonded into the calcium deposits on the rocks and in the sand.  A drop in the Alkalinity ( at such a high Calc level ) is causing these 'old' deposits to reabsorb and therefore release the phosphates back into the water column.

That is why I suggested raising the Alk and also using a phos remover of some kind.  It also explains why the previous owner didn't have the problem.



John[/quote]
John you know me I have to have things spelled out.

The theory is interesting but the alk is or was in proper range of 12 DKH or just a tad high and along with the calcium being high we could wait and see if it did drop by its self.
new2reef2 almost had the same issue but his pH was also off the charts.
Maybe the stirring up of the sand bed and doing a vacuum would tell us for sure.
other then that water changes would be the only other way to reduce quickly. And if found that the sand is the issue then proceed with a change out.
Also think water changes would take out the phosphates the are bound by the calcium.
Oceanic salt when mixed up has been testing with high calcium readings (450 or so) already not like most other salts that were just mixed.

 

Dave,

LOL ;D You and me both, mate.

With elevated levels like this there is no 'proper' range, it is a matter of balance. Have a look at the calc/alk chart we often refer to, the alk for a calc reading of 490 should be around 14+ to be in balance.

Same issue, but different problem, plus his tank was newish. Please remember that the issue I was writing about was the high phosphate and my reasoning of why it was so high.

If I am correct then no amount of sand stirring, water changes, will fix the problem totally.

As a reasonable person I am more than happy to concede that I may be 100% wrong, but I cannot think of another reason for a tank which has full documentation of past reading to now have a high phos reading.

I also asked Cindy ( Hello Cindy ) what the algae levels were like but haven't as yet seen a response as yet. If the levels are within reason I can't really see that there is a problem at all

John

John