This site has a lot of articles about all sorts of aspects of aquarium care, but I want to highlight the three most important improvements I have made over the years. These are the changes that made the biggest differences in my aquariums. They are water changes, diet, and sand. If you only read about three things on this site, these should definitely be them.
Water Changes
I can remember when I used to think that all the good bacteria were in the water. I even remember telling customers when I first started working retail to only do 25% water changes, the most being 50% in big emergencies because otherwise they would lose all their bacteria. It wasn’t until I got in to a heated debate on a forum that someone opened my eyes to the reality.
He talked about how the bacteria are in the filter and that some people do massive water changes (mainly crazy discus people doing water changes so large that the fish are laying on their sides). The point was made and a light turned on. I started doing larger water changes. I stepped up to 50%, then 60%, 75%, and even 80%. My fish did better. The tanks were cleaner and there were fewer health issues. Fish grew better and had better colors.
So for success you want big frequent water changes. In general water changes should be at least once per week. They should be at least 50%, ideally even larger. 25% is the bare minimum and really should be reserved for lightly stocked, heavily planted tanks.
The other part of this breakthrough was how big of an impact water changes have on how heavily stocked a tank can be. We all see ‘rules’ and ‘guidelines’ about x fish per gallon and when stocking is discussed water changes are usually not even mentioned. They are the focus. They are the most important factor in stocking. Although the tank’s volume obviously does have an impact on the size fish that can go in it and a limit to how many, water changes and water quality are an even bigger factor. Big weekly water changes allow for 2-3x the stocking or more that you could otherwise have or may see suggested. I personally feel that anyone who discusses stocking without focusing on water quality and water changes is nothing short of negligent. They are doing a disfavor to everyone who ever receives that information by misinforming them.
For more information read the full article: Water Changes.
Diet
Fish nutrition has come a long way since I started the hobby. I recently talked to someone who talked about how decades ago fish food was literally horse flies that had been collected in big barrels, ground up, and dumped in to the fish food containers. The food was nothing more than ground horse flies. Today we have a very advanced understanding of fish nutrition and a wide array of foods, almost all of which are light years beyond ground horse flies (and even most of the foods that were around when I started). It is hard to believe how big of a difference the food can make. We think if foods are being sold they have to meet certain standards. They all claim to be high quality, complete, etc. The truth is that, although better than ground horse flies, most are garbage. Even some brands considered to be very good are only mediocre at best. New Life Spectrum has proven over and over and over again to be the best food on the market. I have a lot of experience that speaks volumes for this food, but I am far from alone. Almost everyone who tries feeding this food exclusively for a few months sees how big a difference it makes and is hooked. The fish are healthier, grow better, have better colors, and the tanks are cleaner. It even allows fish to thrive that just waste away on other foods.
I really can’t say more than what has been said in these articles:
Myths and Misconceptions About Fish Nutrition
Sand
This one may be surprising to many, after all the substrate itself isn’t usually thought of as having have a massive, direct impact on (most) fish. But, the amount of maintenance a substrate can require, the debris it traps, and the impact on water quality it can have in certain circumstances can be massive. I haven’t used gravel in about a decade now. I first tried sand because I was planning on doing stingrays in a 150. I ended up changing my mind because it wasn’t really big enough for them and I couldn’t properly automate water changes so that the chemistry was stable, but the difference in the amount of maintenance was a turning point in the hobby for me. That tank was by far the easiest tank to maintain. I didn’t have to vacuum anything off the bottom, ever. Water changes were just drain and fill, that was it. Very quickly all my tanks were sand I haven’t looked back. I have a grate cover over the siphon so that fish don’t get sucked up, I start the drain, when it’s drained add Seachem Prime (or Safe, the powdered version), then fill. That’s it. This allows me to do massive water changes quickly and with very little active work on my part. I am not standing there siphoning the whole time. I am not rearranging decor to get to every spot. I am not stirring up junk when I move something at a later time. It is clean and effortless. In addition to all this it is MUCH more natural for the fish. Tons of fish love sifting through it in search of food, exactly as they would in nature.
For more information on sand, check out the fill article: