Sunday, May 15, 2011

Seawater

Ok, while the tank is in it's test phase, we're leaving FW behind and now to saltwater. I'm leaving all the details for you to read re: mineral content and the history of the ocean and it's reefs. Unlike FW, one needs to be concerned about specific gravity (s.g.) and salinity. Salts dissolved in water increase it's weight and density. Now when we add livestock, we have to be concerned about acclimatizing to s.g., pH, water temp, etc.

We need to make sea water to fill our tanks. Hence,the big pre-seawater comment, "I heard it's a lot more work". Anyway, some stuff you'll need (this is what I have):

1) bucket for mixing sea water
2) Storage container
3)El cheapo heater
4) Powerhead to mix the salt (that is the stock pump I removed in the photo)
5) Hydrometer or refractometer
6) Sea salt



Popular consensus:
1) Sea water should be mixed up the day or two before (aged). It should be heated,mixed with a powerhead, s.g. gravity checked...1.021-1.026. pH about 8.2. A recent poll here showed the majority between 1.023-1.025.
2) SW can be stored for several months if kept well-sealed and in a cool place
3) For brands, Oceanic, Instant Ocean and Reef Crystals got most of the highest reviews. However, you may think differently after reading this article: http://reefkeeping.com/issues/2003-03/rs/f...ature/index.htm

Retroedit 06/01/2005 Since starting this thread, Oceanic Sea Salt may have some problems with low alkalinity. Many are switching to Tropic Marin and others are now raving about Catalina Natural Sea Water (bottled ocean water that is purified). If you don't mind lugging a 2 five gallon jugs home monthly, this may be the route to go.

4) The hydrometer is plastic and many of the 'reefers' posted that it 'works when it wants to'. So...I bought a refractometer..one of the corners I elected not to cut.
5) Now...water. The big heated question. SW fish are extremely sensitive to nitrates and excess phophates can cause algae blooms. So....what to do about water? Options discussed include:
a) tap water filter
cool.gif buy distilled water
c) buy premixed sea water either at your lfs or in a plastic bottle on the shelf
d) buy an RO/DI filter ...reverse osmosis/de-ionized..which removes virtually all minerals and contaminants from the water.

What I did: throughout all my FW tank changes, my tap water contained 5-20 ppm nitrates even with a PUR water filter. This is totally unacceptable for a SW tank. Many homes have copper pipes...copper can be toxic. Since I would have to do weekly 10% water changes (2.5 gallons/week), I did the math and figured that my own filter made sense. Again, I think they are cheapest on Ebay.

N.B.

At the supermarket, you can buy the store brand container of steam distilled water for $2.25 for 2.5 gallons, priced here in NY. Here are some calculations if you do not want to foot the cost of buying a filter to make RO water:

--adding water to the 24 gallon cube will require 10 containers at a cost of $22.50
--a weekly 10% water change will cost you $2.25
--minimal water requirements for your 1st year will cost you $22.50 + $117.00 (52 x 2.25) =$139.50.
That already exceeds the price of a RO/DI unit. Just food for thought. For some people who don't wish to mess with this stuff, this may be an option.

You can buy premixed SW at some of your lfs' for cheaper, so I hear, but, you have to rely on THEM for mixing and adding PURE water.

Point of Information for Converting FW'ers

New piece of info for us FW aquarists...when there is evaporation of water from a SW tank, the specific gravity will progressively increase since salts do not evaporate. Replacing the water with sea water is a no-no as this will cause a progressive rise in s.g. You must constantly top off the tank with pure water. Therefore, you must always have pure water stored or on hand.

And now..tank update. My tank temp warmed up to 78.9 degrees and held steady. So..I cut the lights now to see what the setpoint on my heater is doing. It cooled to about 77 degrees, so, I know the heater is set below this temp. SO...I've now added my first DIY ....a fuge light, but not one of the ones seen before and it may or may not work.Now I will put on all lights to see how the temp goes with the fuge light going. More pix on this mod to follow.

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