Fish Keeping Success Abridged

If I Could Actually Write “Fish Tank Success In Only One Page”

(Which you can’t, I mean there’s too much to know, but at least this hits the top ten things a beginner should know, and then “jumping off points” for some deeper searches in this web site.)


Bigger tanks are easier to keep ‘fresh and healthy’. Up to a point (75+ gallons) when they’re a bit burdensome. Don’t keep more than ONE INCH of fish, per ONE GALLON of water in goldfish and tropical fish tanks. A ten gallon tank maxxes out with 10 inches of fish. A 40 gallon tank can have forty fish that are one inches long, or you might even get away with four fish that are ten inches long. You can’t put a forty inch fish in a 40 gallon tank. Restrictions apply.


Don’t buy fish that are lethargic, swim “weird” or have “clamped” (closed) fins. If you buy fish from a tankful of fish, make sure ALL the fish look and act healthy. They all have the same “bugs” –  (after all they live in water). A healthy goldfish has it’s dorsal fin (the top shark-fin) “up” at almost all times. Fish that just shimmy in one spot aren’t healthy. Fish that have patches, blotches, red spots, white stuff, torn or shredded fins are not good purchases.


Whenever you add water, add “dechlorinator”. It turns out, that “SeaChem Neutral Regulator” powder is BOTH a pH regulator AND a dechlorinator in one product. Get it on Amazon or most of the pet superstores have it. The powdered Seachem Neutral Regulator is the best economy in that type of product, without exception. Use the correct amount once a week when you remove and replace 10-15% of the water. SeaChem Neutral Regulator

KEY POINT: If you change a little water every week and add Neutral Regulator, you will practically eliminate water problems.


Once the tank is filled with water, dechlorinated, and achieves proper temperature (76 degrees Fahrenheit) you can “cycle it” with essential bacteria.

Head to the local pond in your neighborhood or “up at the lake” and find a dark-mud-submerged-sticks-and-leaves area near shore with little minnows zipping around in crystal clear water. All you do is scoop up 2-3 kitchen cups of that rich dark mud, complete with sticks, pine straw, leaves, whatever. Drop it in a gallon ziploc bag or better: a bucket. Put some of the pond water in there. Bring it home.

Mix the mud and the water together before using it. Then let it sit for about ten minutes while “most” of the “solid stuff” settles out.

Pour, dip, cup, siphon, transfer, or otherwise collect ONE kitchen-CUP of the “top water” from the bucket or bag per five gallons of water in your tank.

A ten gallon tank needs 2 cups of the decanted water.

A forty gallon tank needs 8 cups of “that good primordial water” from the mud-mix in the bucket. You don’t NEED the solids or the mud, but you need “live” water from it. If you just tossed a tablespoon of that mud directly into the pond it would work great – but it would make the tank physically dirty and that’s not necessary.

This will cloud up your tank. It’s okay, there shouldn’t be any fish in there. Make sure your filters are operational and running.

But by the next morning the tank should have nice clear water.

If you didn’t dechlorinate, or there’s no filtration or aeration, you’ll be disappointed.

If the mud you collected was from ‘bad water’ then you’ll be disappointed.

Bad water for seeding is any water coming from the pond-edge that does NOT match: “….dark-mud-sticks and leaves area near shore with little minnows zipping around in crystal clear water.”


The best filtration for goldfish and tropical fish tanks are sponge filters. Coarse-foam, air-powered sponge filters that look like ‘barrels’ on a center post of clear plastic. Get on and look up “Lustar V Sponge Filter” for examples of what I’m talking about.

The easiest filtration (not the best) is a “hang on” “external box” power filter. It uses cartridges and pads. They’re so easy. They work okay.

Undergravel Filtration also is good. See for details.


All fish (the common species and goldfish)  tend to do well at 74 to 78 degrees Fahrenheit. They sell “submersible tube heaters” that have titanium or steel shafts. These don’t break. It’s nice.

Some are made of glass, and they’re okay.

I like these submersible “presets” best.


Most of the time, fish “diseases” are actually not BUGS. Usually it’s a lack of beneficial germs (the ones you collected at the pond)    or a sagging pH –  which was fixed preventatively by you using SeaChem Neutral Regulator.

Sometimes there really ARE fish diseases.

Here’s all you do:

Step one: Remove and replace 50% of the tank water and dechlorinate.

Step two: Increase aeration.

Step three: Pull out any live plants in the system.

Step four: Make sure the water is at least 76 degrees Fahrenheit.

Step five: Apply salt per the instructions at

Step six: Apply a product that contains Praziquantel according to label instructions.

That’s “Parasites” in six steps. You’re welcome.


Sores and bacterial infections:

These only happen when fish are cold, crowded, in bad water, or have parasites.


Fix your water, heat ‘em, and salt ‘em up. Increase aeration. The infections will take care of themselves.

SIDE BAR:  There is never a bad time to go get some extra “Primordial Mojo” from the pond’s edge to rejuvenate or clarify the tank water.


Highly recommend:  Once your tank is clear and running “pretty nicely” take the step into “live plants” and put some Wisteria, Bacopa, Ludwigia, Duckweed, Anachris or Anubia into the tank. Salt will kill these which is why I said “once your tank is clear and running pretty nicely.”


There are cheap LED strip lights you can just lay on the top of the tank. They cost about $24 a piece and you can get as many or as few as you think you need.

You should run your fish tank lights on a timer, starting when YOU wake up and turning off when YOU go to bed. If you run your lights 24 hours a day, or really, more than 18 hours a day, you’ll end up with an unpleasant amount of green algae in the tank.

If that happens you need a “plecostomus” fish which are cheap and pleasant.

So Fish Tank Success For Beginners is:

  1. Get a big enough fish tank
  2. Use a submersible preset Aquarium Heater and go about 76 degrees.
  3. Always dechlorinate water changes
  4. Start the tank with a bit of natural pond mud, pour off some of the water on top of the water.
  5. Use sponge filters plus-or-minus a hang on power filter.
  6. Recognize and buy HEALTHY fish to start with. Try not to buy fish from a tank of sick fish.
  7. Use a Neutral Regulator and change some water (10-20%) every week.
  8. Use LED lighting less than 18hrs a day – not flourescent strips.
  9. Try live plants once the tank is high-functioning.
  10. If fish get sick, change 50% of the water, heat water to 76-78, aerate highly, and use salt and praziquantel.
Author: Dr. Erik Johnson
Dr. Erik Johnson is the author of several texts on companion animal and fish health. Johnson Veterinary Services has been operating in Marietta, GA since 1996. Dr Johnson graduated from the University of Georgia College of Veterinary Medicine in 1991. Dr Johnson has lived in Marietta Georgia since 1976.