At my wit's end

[Randy Holmes-Farley]

It doesn't surprise me the sand is hard as that is not uncommon, but that it keeps rehardening and possibly using so much calcium and alkalinity is unusual. Maybe you have some bacteria growing in it that are especially prone to push such a reaction in their neighborhood.

 

[Amphiprion]

It doesn't surprise me the sand is hard as that is not uncommon, but that it keeps rehardening and possibly using so much calcium and alkalinity is unusual. Maybe you have some bacteria growing in it that are especially prone to push such a reaction in their neighborhood.

That's certainly a possibility. There's not terribly much I can rule out anymore, since I no longer really fully understand what is happening, short of the obvious--dropping calcium and alkalinity, along with lots of precip. I'm hoping some new sand with an established biofilm, along with added bacteria-rich and infauna rich sand may help prevent this from happening anymore. I initially started this tank with pure dry sand and have had nothing but issues since. I'm just left with so few options at which to point the proverbial finger at this point that I'm just grasping at straws. All I can do it try one particular thing at a time.

 

[chuckreef]

I would suck as much sand as possible out with a large siphon hose during a large water cahnge. If it is the sand (still seems hard to beleive), removing a large portion to a holding container and properly dosing a large dose of two part should reveal an immediate improvement in the low alk problem. If you see such an improvement you can decide to try to get the rest (the sand you could not sipohon out) out (or not if the alk is up.). Then you could add new sand slowly over several weeks time.

 

[Amphiprion]

Okay, updates. I went ahead with my plan and either replaced or covered much of the old sand bed with live sand, hoping the biofilm would make a difference. This is the crazy part: it stopped dropping afterward! I have never had that much trouble with sand and would've never thought it would do something like this, at least to this extent. My calcium has been steady @ ~450 ppm and alkalinity @ 9 dKH ever since I added the sand. Dosing hasn't changed and there is zero clumping, hopefully thanks to the established biofilm on the sand.

 

[Randy Holmes-Farley]

Sounds good!

Happy Reefing .

 

[Amphiprion]

Alright, another update. I'm thinking the bacterial theory may be the case. The reason behind this is that the new sand is clumping . The interesting part is that it is NOT clumping at the surface, but only where it comes in contact with some of the old sand. It is literally at that interface only. If it bugs me too much more, I'll shovel the rest of it out and separate it.

 

[Merfin70]

Wish I had read this months ago though I've since broken down the tank in question. I had a similar problem where my tank just ate through supplementation. While I had some precip on pumps and heaters and the like, the majority went into massive clumps in my sand. Similar to you, I tried everything to boost my levels so I feel your pain in the frustration. Slow supplementation, fast supplementation, didn't matter. I'd go right back to 360 ca and about 6/7 alk.

I'll be interested to see how your fare in a couple of weeks. Subscribed and please keep us updated.

 

[Randy Holmes-Farley]

The interesting part is that it is NOT clumping at the surface, but only where it comes in contact with some of the old sand. It is literally at that interface only.

That is very interesting. Thanks for the update.

What type of sand was the first type?

 

[Amphiprion]

The interesting part is that it is NOT clumping at the surface, but only where it comes in contact with some of the old sand. It is literally at that interface only.

That is very interesting. Thanks for the update.

What type of sand was the first type?

It was CaribSea special grade reef sand (dry).

 

[Merfin70]

Alright, another update. I'm thinking the bacterial theory may be the case. The reason behind this is that the new sand is clumping . The interesting part is that it is NOT clumping at the surface, but only where it comes in contact with some of the old sand. It is literally at that interface only. If it bugs me too much more, I'll shovel the rest of it out and separate it.

How much old sand did you leave in?

 

[Amphiprion]

Only the portions that had stayed loose the entire time and others that were physically impossible to remove without tearing the tank down, since they had cemented rocks together at the base.

 

[BlueCursor]

This is a very old thread, but I am also having this issue. I am hoping other knowledge has come to light on this subject.

It's a rare occurance, based on my searches, but I have it.

This past weekend I pulled out a lot of my dry aragonite substrate. Did have about 2.5 inches, now have 1 inch. I don't like the bare bottom look, no matter how functional it is. So I hate the idea of having to pull out all substrate.

Background:
100 gal tank setup 11/2013.
Dry rock, dry aragonite substrate
Skimmer, LED lights, Sump
Typical cycle stuff, still little bit of diatom but little.
Phosphates: 0
Nitrates: 0 currently, always < 1
Salinity: 1.025 - 1.027 because high dosing of CaCl2 and NaCO3 raises salinity
pH: 7.9
Ca: 380-420
Mg: 1280-1400
Alk: 6.5-7.5

Current Dosing:
Mg: 80 mg /day BRS 2 part
CaCl2: 240 ml / day
NaCO3: 240 mg / day

One moth ago:
Mg: 45 mg /day BRS 2 part
CaCl2: 120 ml / day
NaCO3: 120 mg / day

So the dosing requiement has been going up.

Because the alk is getting sucked out, it is really hard to keep numbers steady. Doing 30% water changes weekly just to keep salinity from running away.

I am not seeing much clumping because I have nassarius (sp?) snails and they turn the substrate over. I do have some in corners. Clumping on rocks under substrate level.

I have been dosing biopellets too, so I am wondering if I have pushed a ton of carbon into the system so now i have a ton of bacteria activity in my substrate, causing this issue. Using BRS biopellets in BRS reactor, about 3/4 full, which is recommended amount. I turned this off about 1 week ago. Really haven't seen any change in dosing requirements, yet.

I am also going to start using Kalk in TO water to hopefully reduce CaCl2 and NaCO3 amounts I have to dose, so I don't raise salinity as fast. Not sure how helpful this will be.

 

[BlueCursor]

I should add, when I removed 1.5 inches of substrate there was a biofilm over everything after the dust settled. It wasn't a film of carbonate (that was there too), but an actual film. When I turkey basted the rocks and LPS, a film came away in sheets off of everything.

 

[bertoni]

[welcome]

That's a very large dose of the two-part, from what I can tell. I'll have to think about this a bit, but I'd probably start by switching to the low-pH formula, the one that's just baking soda. The lower pH will reduce abiotic precipitation, which might be the issue here. Are there any buildups on the surfaces of the tank, the heater, or inside pumps, for example?

 

[BlueCursor]

I am not having a low pH issue. My pH is hovers at 7.9 - 8.05. If anything, I would like it more alkaline. But if I increase alkalinity dosing it does just precipitate.

By adding Kalk to ATO, I am down to 130 ml Alk and 90 ml CaCl. Seems to hold steady at 120 ppm (7 dkh) Carbonate and 410 ppm Ca. So I am at NSW levels, but it seems a ton of stuff going into the water just to maintain it. I see nothing in the way of precipitation on heater, etc. Still, pH hovers at 8.0.

Regular GFO from BRS does not seem to precipitate CaCO3, but the high grade stuff will. I have gone back to regular GFO until this issue resolves itself.

I also added Cheato two weeks ago. It has quadrupled in size in two weeks. So I obviously have lots of nutrients even though NO3 and PO4 test show 0 (Hana PO4 and Red Sea NO3). I also took a sample yesterday to the LFS to have them verify Ca, Alk, and Mg. They were very close to my test results (within 5%). We can eliminate testing error.

 

[bertoni]

One issue with the high-pH formula is that it can cause precipitation locally before it gets distributed throughout the tank, which might be what's happening here.

Is there a lot of coralline growth, or maybe a large clam in the system?

 

[BlueCursor]

Virtually no coralline growth (annoying but probably due to low alk and swings in parameters). No clams. I have about 20 snails, one lord acan (19 heads), one folded brain (3 lobes), one Duncan (9 heads), a trumpet (3 heads), and the rest is non-calcium stuff like zoas, mushrooms.

I dose straight into the sump. I see very little precipitation at the end of a week and nothing on heater. I could try some of the low pH stuff and see how that works out. When the Alk doses, I see very little cloud, and it almost instantly vanishes. I actually thought this could be an issue and I put a small power head in my sump right where the dosing goes into the sump. This has virtually eliminated any precipitation I can see; however, hard to tell about what I don't see.

I really think the op of this thread was right with his conclusion his problem was bacteria. I can't shake the thought that I have a ton of carbon fed bacteria consuming even more carbon via carbonate. When I pulled out a bunch of gravel the dosing requirement did seem to go down. I am going to leave biopellets off and see if the carbon reduces and alk requirement goes down. After 1.5 weeks of no biopellets, my nitrate is still 0; however, I do have Chaeto now so that is going to help the nitrate issue.

I have to say, the Chaeto is having great growth. Having had freshwater planted aquariums for over 10 years, I know plants and algae. This stuff is finding way too many nutrients in my water with this kind of growth. I am surprised since my PO4 and NO3 are at zero. But it obviously is pulling lots of stuff out of the water so that can also explain high bacteria counts. The Chaeto is also floating because it has a lot of small bubbles in it. I only see this in freshwater planted aquariums when I would keep the CO2 injection up so there was good CO2 for the plants. Another indicator that I have lots of bacteria because of the high CO2 indicator. I am running a big skimmer 24/7 though, so water is aerated well. I am also turning over the tank with the sump 10+ times and hour.

 

[bertoni]

Generally, only organisms that produce calcium carbonate will consume net alkalinity from the water column. If nitrate is exported via water changes, that will remove some alkalinity, but the total amount tends to be small.