dosing and water changes

[revance]

I am an experienced freshwater aquarist and have bred many fish (mostly angelfish), but have never ventured into any marine tanks. I am considering setting up a nano reef tank but have some questions first.

 

Is it possible to completely avoid dosing the water with additives by doing regular (possibly daily) water changes?

 

I have a 30 gallon flat back hex that I was considering using. I may just buy a new tank because it is possible the tank might have had medications etc. put in it. If it has, it would have been over 10 years ago, so it might still be safe (any opinions on the matter?).

 

I already have a spare trickle filter, UV sterilizer, submersible heaters, and many powerheads. If I buy a skimmer and some good lighting (probably PC) would this be an ideal setup?

 

I don't mind doing many many water changes, but there is nothing I dislike more than doing daily water tests and juggling a dozen different additives. In my large planted tank everything that can possibly be automated is automated... all I worry about is doing water changes religiously (and ocassional tests). Given the size of the tank and filtration I would be using... what kind of water change regiment would you suggest? Would 5 gallons a week or 5 gallons twice a week be sufficient?

 

Any other suggestions are appreciated!

[rehren]

10-20% weekly would be more than sufficient given you have a nice natural filtration setup.

 

i'm sure the old tank is fine after a good rinsing with warm water.

 

i also suggest you read all the articles available at: http://www.nano-reef.com/info/ before posting more quesitons on topics that may already be covered.

[Isaka]

Whether you need to dose or not depends on what you plan on keeping. Some LPS/SPS can consume elements from your water at a faster rate than water changes will cover. My tank is all softies and 1 lps and my levels are all fine (never dosed). I do water changes every week only.

[Tempest]

You will most likely need to dose regardless of how much water changing you do. Heres a crude example:

 

Each gallon of saltwater has 5mg of element X. If you have 10 gallon tank thats 50mg. After a week the tank inhabitants reduce the amount of X to 40mg in the 10 gallon tank. You replace 1 gallon. You've added 5mg, but the tank used 10mg. This isn't 100% accurate with the math, but you get the picture.

 

Do NOT dose anything until you've measured for it. Rates of depletion will vary based on what's in the tank and chemical interactions. For example, just adding calcium may not be enough if your alkalinity is too high or too low or you have deficient magnesium. Good articles on tank chemistry can found at www.advancedaquarist.com

 

Here's one on calcium and alkalinity www.advancedaquarist.com/issues/nov2002/chem.htm

 

Finally, if you ever used any copper based medications in the 30 gallon tank do NOT use it for a sw tank. Copper gets absorbed into the sealings and is lethal to inverts (and everything else at a high enough dosage). The amount absorbed may be minimal, but why take the chance when a glass tank is relatively cheap.