what is the easiest way to keep ph neutral in fish tank?

Easy, ignore it.

Natural water is seldom at a neutral pH, and may even vary significantly with the seasons. Some fish naturally come from water with a pH of 5.5, others from 8.5, others don't really care.

Find out what the pH of your tap water normally is, and choose fish whose natural range matches.

Loches, tetras, Sth American Cichlids usually prefer a lower pH, 6-7 range. Most fish are perfectly happy with 6-8 pH, while some like it up 8-8.5 (African Lake Cichlids and mollies for example).

Many people stress over the pH of the water, when most of the time it simply doesn't matter, and when it actually does, you can seldom fix it by in pouring random chemicals.

Ian

If you have 4 goldies I'm assuming you have an adequate tank size, of at least 50+ gallons as goldfish require 10-15 gallons per fish. I also recommend a filter that handles double the capacity of your tank. I have four goldies in a 55 gallon with a 110 gallon rated filter. Without an adequate tank and filtration system you are setting yourself up for ill and dying fish. Is your tank cycled? A cycling tank should be tested every other day. A cycled tank can be tested once a week. All fish owners should have a drop test kit on hand for pH, ammonia, nitrites, nitrates and hardness/softness. Goldfish require cooler water of 60-75 F. They require alkaline water, which is the pH and since a 7.0 is neutral they require a pH of 7.2-7.8. You'll need to make sure you get a kit with a 'high range' pH test for this. The ammonia needs to be 0 ppm, nitrites 0 ppm and nitrates less than 20 ppm. If any of these are off it can cause stress, illness and even death. The only way to correct water quality issues is with water changes...50% emergency changes in extreme cases with 20-25% daily or every other day until the problem is corrected. You can also use Kordon's AmQuel Plus to detoxify any ammonia or nitrites in the water so that the fish do not get ill but use this with caution in a cycling tank because you will be neutralizing it and not allowing the nitrogen cycle to complete. Good luck.

You will never, ever, be able to keep a constant pH all the time. It naturally will read slightly lower first thing in the morning and slightly higher first thing at night, just from the action of plants and algae and fish respiration on the water.

Many fish have a range well around neutral, and some want nothing near neutral. Are you even sure that in your attempts to stabilize at neutral that it is a pH the fish even want?

The answers about the extremes are correct in general. All fish have an ideal range for pH and as long as you are close within that range, and keep it relatively stable, then you will be fine. The tip is to try to match fish species to the pH you already have, rather than buy fish that want high pH and you only have low pH or visa versa.

Also, a pH problems usually indicates problems with more important water parameters. High ammonia or high nitrates can cause pH to be out of whack for example. So rather than focus on pH, turn your attention to other water parameters. Usually if you keep them in check, pH follows right behind.

Unless your pH is above 8.5 or below 6.5, altering it is totally not necessary and can actually be harmful if you don't know what you're doing.

Just leave your pH alone. If you HAVE to, for some reason, lower it a bit, using Reverse Osmosis water to mix with your tap water will help reduce alkalinity and pH. If you HAVE to bump it up a bit, using a substrate like crushed coral, or adding limestone to your tank is a more natural way to buffer the water.

Water in the wild is not a pH of 7, and fish from all over the world live in all kinds of pH's of water, ranging from around 5-9 depending on the species and where. Fish in the aquarium trade are, for the most part, quite adaptable to whatever your tap water's pH and alkalinity are.

Your question could actually have a very long answer..... I hate to answer a question with a question but if you could share what types of decorations and everything in your tank as well as the system and fish you have and also where does your pH tend to drift to, that would help a lot.

The chemicals you mention do help but the forces withing your tanks are resisting it well and finding why is the answer to your question.

Frequent partial water changes can help dramatically. If you never change water or change it too much, have live plants, drift wood, or crushed shells and certain types of rock, and other factors can cause issues as well.

Because you didn't provide too much details, I recommend you go to a private fish store rather than a chain store and have a good conversation with a knowledgeable hobbyist.

Good luck to you!

Fish usually don't have a problem with small pH changes. My pH is always high just because of my water supplier.

Most fish will adapt to a PH that isn't ideal. So long as it isn't extreme in one direction or the other, don't worry about your PH. It's more important that it be stable than perfect.

u could go to the store and buy ph decrease or clean the water