1. Water conditioner
API stress coat vs Seachem prime
Both of these manufacturers are reputable, arguably just about the best in the business. But they also both produce a few unnecessary and detrimental products, and their reasoning for using some of them is misleading at best. Neither of these conditioners are really the "best," depending somewhat on circumstances.
StressCoat contains aloe vera and studies have concluded that long-term the gills of fish are negatively impacted. There is really no reason to ever use this product.
API's
Tap Water Conditioner is far safer and more effective because it deals with what needs dealing with, chlorine and chloramine. The heavy metal detoxification is found in most conditioners and is probably worth it, just in case. Fish have a much lower tolerance for some minerals such as copper than humans, so what is safe for drinking water is not safe for fish. This product is also the most highly concentrated conditioner available, so less is needed which benefits fish. Conditioners like every substance added to the tank water get into the fish's bloodstream so additives need to be essential and then used minimally, never more that what is actually required to handle the task.
Which brings me to the
Prime. This messes with the ammonia/nitrite/nitrate chemistry and this is best left to the bacteria and plants. Here again there are unnecessary chemicals getting into the fish. Think of it like taking antibiotics when you don't need to; it is not going to help the fish, and over time seems likely to do the opposite. However, in new tanks this can help initially, and if you have ammonia/nitrite/nitrate in the source water (at minimal levels to begin with), a conditioner that detoxifies these can help, by making the water initially safe, and by the time Prime becomes ineffective (24-36 hours) the bacteria/plants will be able to carry on. With excessive nitrate though this doesn't work either.
Bottom line...the water conditioner should only do what needs to be done with your circumstances, never more unless it cannot be helped, and always use the minimal amount. Claims by several manufacturers that overdosing is not harmful are false. They obviously define "harmful" as meaning the fish die within hours, but any product that unnecessarily gets into the fish's bloodstream can be harmful long-term without killing the fish outright.
2. Sludge management
API Stress zyme vs Seachem Pristine
There is no way to handle sludge except regular substantial water changes, while not overstocking, overfeeding, and with regular substrate and filter cleanings. Plants also help, and the substrate can be left alone with plants, provided the other factors are in line. And here again, this chemical compound is doing more harm than good by entering the fish.
Pristine I am not as familiar with but having read Seachem's information, all I can say is, if you really think you need sommething like this, you clearly do not have good aquarium husbandry/management. There is no way any aquarium should ever have organics/sludge that is not easily and readily dealt with naturally by plants (if present) and/or bacteria.
3. Adding nitrifying bacteria
API QuickStart vs Seachem stability
Bacterial supplements can help, some much more than others. One must however realize that they are not instant cycling products (except for
Dr. Tim's One and Only). Tetra's
SafeStart is second as the best (it was developed by Dr. Tim Hovanec too). However, studies Dr. Hovanec and his team carried out on some of the other products did show they would speed up the colonization of the nitrifying bacteria, though not as much as the other two I mentioned; the other products did not (at least then) contain the specific nitrifyting bacteria species, but the bacteria they did contain did help. I have used
Stability once when I had a bacteria issue following a treatment and without question it got the ammonia and nitrite at zero within hours. But whether that was just good fortune, I cannot say. But others have used
Stability with good results during cycling, so it can't hurt. Just don't assume it is better than it actually is.
