[kimmeewoo]

What could cause this? It's 4-5 inches deep and I know it's functioning because I can see the air bubbles and worm trails along the glass.

Is it calcification? I occasionally dose with B-Ionic, but nothing else. Sometimes when I add fresh water, I see little white/clear flakes blow off the sand bed. Any suggestions?

[Ninong]

What are your readings for:

• pH
• Alkalinity
• Calcium

Also, what exactly did you use to construct your sand bed... the exact products used? I'm trying to determine particle size distribution.

Ninong [img]/ubb/smile.gif[/img]

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Irrational Exuberance!

[SPasse]

Kimmeewoo,

Also test for your magnesium level.

Regards,

Scott

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The definition of an expert is a washed-up drip under pressure.
You can see my reeftank at http://www.homestead.com/spasse/

[Ninong]

Kimmeewoo ~

I think I'll do an end run around what SPASSE is getting at and just ask what brand of salt mix you are using?

Ninong [img]/ubb/biggrin.gif[/img]

P.S. - Scott, how do people who have low levels of magnesium get into that situation? Is it because of lousy salt mix? Some folks claim that Kalkwasser (which Kimmeewoo is not using) can form magnesium carbonate and magnesium hydroxide but Craig Bingman says that's not true. Do you think the "clear white flakes" are magnesium calcite???

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Irrational Exuberance!

[kimmeewoo]

I will check my pH, Calcium, and Alk levels when I get home. I don't have a magnesium test, though. I use Instant Ocean salt and tap water. (According to Fortune Magazine, Salem has the best tap water in the country. I have the water chemical composition sheet if that information would be helpful.) My sand is 100% Southdown.

I should mention that I only notice the clear/white flakes immediately after I does with B-ionic. For instance, if I dose first, then add my top-off water.

[This message has been edited by kimmeewoo (edited 05-18-2001).]

[calypso]

Sounds like precipitation of ions. Overdosing calcium/buffers will turn your sand to cement when they precipitate. Maybe you don't need to use much B-ionic, if at all. Your tests will determine that.

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"The first rule of
intelligent tinkering is
to save all the pieces."

[seado]

I am getting the same thing. I too have 100% SD, only about 3" now but was planning to add live sand to top it off, this week. I also dose Bionic and I get white stuff floating in the water, tannish powder on glass and in places on the sandbed and on some of the rock. My tank is 120 gallon. Alk is 4.34, KH 12.2 pH 8.33, Ca 390, SG 1.025. I use RO/DI and IO salt. My sand bed still seems to be powdery, though I have not really checked to see if it is "hard" in places. I have a newly cycled tank with no detrivore kit or clean up critters yet (only 2 snails that came on the rock. Was planning to add with live sand. I'd be interested to know what you all think this problem is and any suggestions.

[kimmeewoo]

My declaration that my sand bed is hard was based on a remark that my husband made to me when he was moving some live rock around. When I checked it myself this evening, I think "hard" is an overstatement. Perhaps some parts of my sand bed are more "firm" than others, but certainly not "hard" like I thought he meant.

In any case, if it's still relevant, here are my stats, using Salifert tests:

pH 8.2
dKH 10.4
Ca 325

I'm new to performing the Ca and dKH tests, but isn't the dKH too high? What causes that? I know the Ca is low. What can I do about that combination? The two-part B-ionic is supposed to raise them both. Can I add just the calcium component without the alk component?

I forgot to mention that the other additive I have been using on a semi-regular basis (maybe 5 times in 2 weeks) is SeaChem's Marine Buffer, trying to increase my pH.

[wgscott]

The marine buffer is bicarbonate/carbonate/carbonic acid, which is why your alk is too high. My suggestion is that you stop adding all of these additives and you start doing 20% water changes every day or two for the next couple of weeks. This will help to restore a more natural ionic balance. What is happening is that calcium is being precipitated out by excess carbonate (buffer). Magnesium hydroxide won't be a problem until the pH gets up to about 10 to 11, and everything would be dead at that pH anyway. It is calcium carbonate.

[wgscott]

You might also find this of interest:
http://www.animalnetwork.com/fish/li...=&RecordNo=181

[kimmeewoo]

Interesting, and I don't know what to think. Dr. Ron responded to my question on Reef Central and said it was most definitely a buildup of bacteria due to too little fauna in my sandbed.

In any case, I will do a water change.

[Ninong]

Originally posted by kimmeewoo:
Interesting, and I don't know what to think. Dr. Ron responded to my question on Reef Central and said it was most definitely a buildup of bacteria due to too little fauna in my sandbed.

Kimmeewoo ~

You are NOT getting conflicting advice here. Dr. Ron advised you that if your sandbed is hard, it is most probably due to bacterial excretions gluing the sand together and that this indicated an excess of bacteria which could happen if you had insufficient infaunal predators on the bacteria--wormy critters, etc. This can result because the proper wormy stuff was not introduced, or it can happen even if a person did add the right detrivore kits but then added some predators (like the dreaded white burrowing sand star Archaster typicus or too many peppermint shrimp Lysmata wurdemanni) that wiped out the wormy guys in the top of the sand bed which would have the effect of screwing up the infaunal balance in the entire sand bed.

I would like to give you an except from the link that wgscott provided:

3) Bacteria secrete matrix substances that act like organic glues. Increasing the mass of bacteria in the sand by giving them a new food source might result in the production of more of these glue-like substances.

The solution is to stock the sand bed with a diverse population of polychaete worms and other critters that feed on the bacteria and keep the populations in balance. This is also something that seado should do ASAP. That is why Dr. Ron recommends the detrivore kits from both www.ipsf.com and www.inlandaquatics.com -- the alternative would be to use a few pounds of very live sand from a reliable reef tank that already has these populations of worms in it. The wormy critters should be added immediately at the end of the cycle--once the nitrites are down to zero--and before the introduction of fish.

I would agree with wgscott that you should stop adding the buffer. Your pH of 8.2 is exactly the same as natural seawater, your alk is within the desired range for a reef tank but higher than natural seawater, and your calcium at 325 is about 100 below where you would want it to be.

Ninong [img]/ubb/biggrin.gif[/img]

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Irrational Exuberance!

[kimmeewoo]

I did well in my college chemistry course, but the Chemistry School of Reefing Hard Knocks makes me feel like an incompetent! I don't understand why my alk is significantly higher than seawater, but how it can still be within the desired range for a reef. What is the desired range?

If my alk is OK, maybe on the high side, should I continue to dose the B-Ionic to raise calcium? Can I just dose the calcium component without the alk component?

Seawater is 8.2 pH? I thought that 8.3 was ideal. No?

I really felt ready to jump from the FOWLR to a reef, but I feel like I'm in over my head!

[Ninong]

Originally posted by kimmeewoo:

I did well in my college chemistry course, but the Chemistry School of Reefing Hard Knocks makes me feel like an incompetent! I don't understand why my alk is significantly higher than seawater, but how it can still be within the desired range for a reef.

This is because the chemistry of natural seawater in the ocean as a whole is not exactly the same as the chemistry of natural seawater over a coral reef. There are slight differences. But the real reason is that experience has taught that maintaining alkalinity in reef tanks at levels that are a little higher than natural seawater will provide an additional margin of safety in buffering.

What is the desired range?

The recommended range for reef tanks is 8-12dKH.

If my alk is OK, maybe on the high side, should I continue to dose the B-Ionic to raise calcium?

Your alk is on the high side due to the additional buffer you were adding. As recommended by wgscott, it would probably be better to discontinue adding buffer since you are also adding a two-part additive.

Can I just dose the calcium component without the alk component?

You should dose both components according to the manufacturer's recommendations.

Seawater is 8.2 pH? I thought that 8.3 was ideal. No?

Seawater is 8.2 but calcification will proceed at a higher rate at a pH of 8.4, therefore, many hobbyists prefer to maintain their reef tanks at 8.3-8.45pH instead of 8.2--this is strictly a matter of personal choice. Raising the pH above 8.3 can have deleterious effects on some of the other animals that are customarily kept in reef tanks, like Tridacna spp. clams, for instance, which are better kept at 8.1-8.3pH according to Daniel Knop, an expert of Tridacnids.

I really felt ready to jump from the FOWLR to a reef, but I feel like I'm in over my head!

No, you're not over your head. [img]/ubb/biggrin.gif[/img] There are many 14-yr olds who have not taken high school chemistry who successfully maintain reef aquariums. But you will feel more confident in your decisions if you read one of the excellent books that are available on the subject of reefkeeping.

Ninong [img]/ubb/biggrin.gif[/img]



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Irrational Exuberance!