Saltcorner
By Bob Goemans
By Bob Goemans
Dear Dr. Goemans:
I would like to start this email with my sincere thanks for your dedication to making this a better hobby. Your commitment to sharing your knowledge to help hobbyists succeed at keeping marine life means a lot to me, and I'm sure many others. I feel I can trust your advice above all others because you have no obligations to promote specific brands, and I've followed your advice on several occasions with no bad results. It is hard to find a source that I can trust.
I have several questions for you. My first one is concerning a snail called Nassarius. They are a detritivore featured in a Coralife News publication volume 1 number 5. I see this publication at local retailers often. In the article entitled Detritis, Part 2 by Dr. Ron Shimek the Nassarius snail is cited as a good detritivore. One of my local dealers is claiming that not only are they detritus eaters, but they then feed it to your corals. I purchased some because my curiosity was piqued, and they are excellent detritus eaters and pretty cute. I enjoy having them, but I haven't witnessed any behavior indicating that they are feeding my corals. Have you heard of any such behavior?
The second issue I'd like to share with you is using the Aquarium Pharmaceuticals Tap Water Purifier Deionizing unit to mix salt water. In the directions it says that it isn't necessary to buffer the deionized water or adjust the pH because a quality salt mix will set the pH at 8.3. I used Instant Ocean salt mix and let the buckets mix overnight with a powerhead in them (outlet pointing up to break the surface of the water for aeration). The next day the pH tested at 7.4. Have you done any research on this product? I was hoping to eliminate introducing the phosphates & silicates in our local tap water to a new reef aquarium. I've used this unit for a year for my freshwater tank with satisfactory results. Any feedback you have on why the ph was so low would be greatly appreciated.
The next question I have for you is about Venomous Cone Snail identification. I have one picture of the dangerous creature in one of my books, but I'd like to know if you have any suggestions on where to further research this snail. I'm the kind of person that needs pictures, so if you know of some good sources of information with pictures please let me know. I have recently found a strange new snail in a reef tank I maintain that is scaring me. It is about 1/4", has a white shell shaped like the Nassarius snail with a spiraling row of black dots from one end to the other. The antenna is clear with tiny black dots.
My final questions are regarding plenums. In your Live Sand Secrets Booklet you mentioned that you were going to try a Plenum on a discus tank. Have you started that yet? Also, the people who have negative opinions of plenums say that there is a great danger in the possibility of the plenum water being released into the system. You didn't really address this issue in your book; what do you have in response to this?
Thank you very much for your time. I look forward to hearing from you.
Wendy Floyd
Hi Wendy,
Thanks for your email, and Nassarius is in a scavenger class of mollusks and is said to feed on dead or decaying matter. Yet, most whelks are carnivorous. Not being a scientist, such as Ron, I would tend to go with what he say's until there is firm evidence to counter that position. I've not received anything counter, nor have I personally tried them.
As for the small water processing devices that temporary hookup to the faucet, they are fine for certain situations. The main problem is their size and that water first does not flow through an RO system to remove the majority of unwanted elements prior to it encountering their resins. Because of that, their resins quickly become clogged and their filtering capacity thereby quickly diminishes. For small aquariums, especially freshwater or small seawater aquariums, they may at first use be quite effective. However, for larger aquaria or more complex systems, more elaborate RO/DI type equipment must be considered. As for their product water, yes most or all of it free from the carbonates that help buffer our seawater aquariums, which in turn help to further buffer newly mixed seawater. In fact, I use Instant Ocean most of the time and in using processed water, find it mixes most of the time to a pH of 8.3 with good aeration (powerhead with an outside air supply). Hopefully you have checked the kit used on another source, such as the aquarium to be sure of an accurate reading.
As for further research on snails, try getting Encyclopedia of Marine Invertebrates, Edited by Jerry Walls, ISBN 0-87666-495-8, published by TFH.
As for a plenum releasing its contents into the bulk water, nothing could be further from the truth! All the details on sandbeds, whether in aquaria or the wild is fully explained in our CD-ROM book called "The New Wave." However, I won't leave you without the following explanation;
"Another fact to consider is there must not only be proper oxygen gradients, they must be accompanied by the proper sequence of electrical charges for efficient use of energy. That can not occur in deep sandbeds used directly on the aquarium bottom or inside that of live rock! The deeper the sand/rock, the more negative it becomes and the more the nutrients are attracted to lower depths. But the same is not true for the plenum system because one of the main purposes of the plenum is to retain a small amount of oxygen, thereby having a slightly less negative redox than the sand above it. This change in the sequence of the diminishing electrical charge with depth sends oxidized elements back to the bulk water, recycling elements instead of accumulating them as what occurs in the deep sandbed on the aquarium bottom."
If really interested in fully understanding sandbed processes, read our CD book. That and other very interesting things are discussed, all checked for accuracy by a biochemist.
In fact, here's the latest comment received - "I'm into chapter 5 of the book now and very much enjoying the information in there :) I've already used some of the more basic information to correct a couple of plenum-related discussions on one online bulletin board! ;) Will take me a while to get to grips with coupling and decoupling of nutrient cycles although I do begin to see how a plenum sandbed is reliant on a completely different set of energy pathways than a non-plenum sandbed system. It also makes sense to me why Ron Shimek promotes so-called deep sandbeds over plenum systems given his love of benthic invertebrates! Both approaches can work, but the plenum system works quite differently and depends far less on the vagaries of benthic invertebrate population dynamics. I also like the way the plenum pushes equilibrium away from storage and towards export. Deep sand beds without plenums would tend to store more, and therefore are more at risk of 'old-tank' syndrome. And this explains Dr Shimek's recent interest in that very phenomenon. Craig Dolphin"
Hope this helps,
Bob
