Coldwater Chemistry 3/27/2009
Bob Fenner,
<Robert>
I've used your articles as a resource before, and I gotta say that you are doing a fine job. I am working on a coldwater marine setup right now, with everything stocked from the San Diego coastline.
<Oh! I/we live in East La Jolla... Ok! Mira Mesa>
The primary habitat I am trying to create is the lower zone of the kelp forest. I was wondering if you knew about any differences between coldwater chemistry vs. tropical?
<A little>
If you can tell me about the alkalinity, calcium, iodine, nutrients, etc., that would be great.
Regards,
Robert Bertino
<These measures should ideally be the same as for tropical systems... really, the only difference is temperature. Bob Fenner>

pH question; cold water.- 02/04/09 Hi Marco, <Hello Ross> You've been most helpful answering questions I have had in the past. I hope you don't mind that I emailed you directly. <Not at all.> To remind you: I have a 100 gallon, cold, salt water tank. In the past, I wrote you because my nitrates were high and I had a sea star that was ripping itself apart. <I remember.> Currently, I don't have a lot in the tank ( 7 brittle stars, 3 urchins, couple of snails and a hermit crab). When I had more critters in the tank I had the high nitrate problem and the pH would fall slightly over time (8.4 to say 8.0). Now that the load on the tank is so much smaller, my nitrates are fine but my pH is really high (8.6-8.8). Part of my problem is this: because I work in a school science lab, our tap water is treated so that it is very basic to counterbalance any acids poured down the drain. So doing frequent water changes won't bring down the pH because the water I'm using is so high to begin with. I just tested the Alkalinity of the water and it is very high as well (3.6). I don't really want to buy bottled water because that could get expensive. Should I use some sort of "pH down" (which I think is just sulfuric acid) or should I not worry about it. Hopefully, we will soon be getting some new critters so the pH might start to drop due to natural processes but I don't want them to have pH shock when I put them in the water. Suggestions? <First it has to be noted that a stable pH with a slight daily cycle is more helpful than having exactly the wanted pH. Second: the pH of cold sea water is often higher than in tropical sea water. However, values above 8.2 are rare, and 8.6 usually only occurs in coastal cold water areas with very high plankton occurrence (and sometimes tidal pools). Third: Some electronic pH meters have no automatic temperature compensation and will give you wrong numbers when used in cold instead of warm water. Four: Check if the salinity of the tank is as you would like to have it. High salinities can be related to high pH. There are several options how this problem can be solved: My personal approach would be to invest into a simple Reverse Osmosis (RO) unit. This should easily solve the pH problem and also help to improve water quality by holding back a lot of unwanted ions. Careful dosing of diluted sulphuric acid <<Mmmm, VERY careful... there are some products made of H2SO4 outside the U.S. for ornamental aquatics use... But not in the States... DO take great care if using. RMF>>  or commercial products to lower the pH, as you noted, is an alternative method, but you would have to use a metering pump or a DIY unit to let it drip slowly into the tank (into an area with high current or preferably the sump) to avoid pH swings. However, adding accidentally too much could be fatal, pH swings due to irregular addition would also potentially disturb the biology of the tank. Also, you note the water of the lab is treated, what about the water in other parts of the school? The use of tap water is discussed here: http://www.wetwebmedia.com/water4maruse.htm . When adding new animals from an environment with a lower pH the acclimation process has to be undertaken very slow by dripping tank water into the bucket with the new animal over several hours as described here: http://www.wetwebmedia.com/acclimat.htm . The higher the pH difference, the longer the acclimation period should be.> Thanks. Ross <I hope this helps. Marco.>

Coldwater Marine Fish Flukes, Copper and Praziquantel Hello, <Anthony Calfo in your service> I have had some wild-caught vermilion rockfish (a Pacific Northwest species) undergoing copper sulfate treatment for months for monogenean gill trematodes, and it has not worked.  <yes... it seems that they bury deep enough that a fatal dose will kill the fish too.> (We have taken gill biopsies to monitor response to therapy.) The fish are still in their quarantine tank. I am considering switching to Praziquantel 1ppm for at least a week. Are there any problems doing both at the same time? Or should the copper be removed before starting the Praziquantel? Many thanks in advance, Lisa H. <Lisa, I would discontinue and remove the copper and use Formalin baths (short and long with your discretion evaluating the fish). Shown to be quite effective on gill flukes at 2-4 ml (35-45% solution) per 10l of water for 30 minutes (SHORT) and/or 1-2 drops per gallon every other day through treatment (LONG). Best regards, Anthony Calfo>