Water changes and you

Or…welcome to our ‘ool’

Water changes are incredibly important to the health and longevity of aquarium inhabitants. There is no magic liquid, tablet, or filter media that will replace regular partial water changes. Your fish are swimming in their own toilet – and it is up to you to clean it for them!

Luckily, cleaning your tanks doesn’t have to be difficult or time-consuming. In this step-by-step guide, I will show you how to perform water changes in a way that will minimize your effort and be easy on your fish and bacterial communities.

Thanks to Aaron over at Uaru Info for giving me the idea for this post! Check out his great blog here.

Step 1: Gather your supplies

– fish bucket

Everybody needs a fish bucket. Use a dedicated bucket that is only for aquarium use. Plastic buckets should be rinsed well and then filled with hot vinegar water and left overnight. Use about 1 cup of household white vinegar to a bucketful of hot water. Rinse well the next day, fill with plain hot water, and allow to sit overnight. Rinse well again, and you’re ready to go! This leaches toxins out of the plastic and makes it safe for use with fish.

– Gravel vacuum and hose

I use a kit that connects directly to my faucet, but you can use the bucket method.

– Dechlorinator

– Other chemicals (Aquarium plant fertilizers, blackwater extract, salt, etc.)

– New filter media

– Towel (to clean up spills and dry your hands when switching tasks)

– Trash can

– Thermometer

– Test kit

Step 2: Wash your hands and arms

Wash thoroughly without soap. You must remove oils, lotions, and perfumes from your skin. These things will end up in your tank if you aren’t careful, and can be harmful to your fish.

Step 3: Remove water

First, turn off as many lights as you can spare and get them out of your way. The last thing you want is to knock a light strip into the water and shock yourself.

If you are using a hose and bucket to change the water, you can opt to start the siphon by mouth or by dip method. Dip method means putting the whole hose into the tank and allowing all of the air to escape the tube. Then, cap one end with your thumb and pull it down into your fish bucket. Remove your thumb and the siphon will start. I find this to be too much effort, so I start siphons by mouth and cap the end with my thumb before the water gets to me. I have gotten more than a few mouthfuls of fish water over the years – it hasn’t killed me yet, so I don’t worry too much about it.

If you are using the type of vacuum which hooks directly to the sink, then remove the aerator from your faucet and screw the adapter into place. Simply turn on the cold tap to begin draining water. Check on the sink very often throughout cleaning to make sure the drain hasn’t been plugged by plants or debris coming through the tube.

The general rule of thumb is to change 20% of the water each week. This is a bare minimum. Years of experimentation have convinced me to change between 30% and 50% in all but the most lightly stocked tanks. My goldfish tank gets 50% of the water changed each week, as goldfish are heavy feeders and produce a lot of ammonia. This also holds true for other large, messy eaters who will benefit from the extra cleaning.

My 55-gallon blackwater tank currently houses a group of eleven quarter-sized angelfish which I am raising for breeding stock. This means the tank is overstocked. In addition, the angels are getting four feedings a day. Because I must maintain excellent water quality for the benefit of the fast-growing angels as well as the permanent residents of the tank, I am changing 40% twice a week. When I break the angels out into separate grow-out tanks in another month or so, I will go back to changing 30% of the water once a week.

While draining water from the tank, be sure to clean the gravel. There is no need to push the vacuum deep into the bed – you are simply trying to remove debris from the surface. If you keep live plants, be sure not to disturb the root systems.

Be mindful that some fish are very curious about the vacuum in the tank. Small fish who get too close can be sucked up. If this happens, stop the siphon with your thumb, raise the end above the tank, and very slowly and gently release the siphon. You may need to tap the vacuum on the tank rim to get the fish out. I had it happen once and the fish was just fine afterward, although he was down a few scales for a while.

Be mindful of curious fish inspecting the gravel vacuum

While draining your tank, do not allow the heaters to be exposed to the air. The sudden temperature difference can shatter the glass tube or damage the heating element. If you use the non-waterproof type of heater (these must be hung off the tank rim), then unplug them at least 15 minutes before you start the water change, and plug them back in 15 minutes after you’re done filling to allow the internal thermometer to adjust itself. If you use the submersible kind, then you simply need to ensure that they remain under the water surface.

If you do have a heater tube shatter, get your hands out of the water immediately. DO NOT try to pick up the glass or remove the heater while it is plugged in. It can and will shock you, potentially quite badly. Unplug the heater immediately and take great care while removing the heater and glass from the tank. The danger of electrical shock when working in a tank is not something to take lightly.

When you have finished draining water out, stop the siphon or turn off the tap.

Step 4: Clean the filter

I am demonstrating filter cleaning using a Fluval 305 canister filter. The principles for other filters are much the same. Read the instructions for your individual filter as to which filter media to use and which order it should be placed in the filter.

First, turn off and unplug the filter. Pour the water into your fish bucket and remove the media. Disposable media like filter floss should be changed each time. Ceramic rings, bioballs, etc. are for bacterial filtration, and are not discarded unless they become so clogged with debris that they cannot be rinsed. Simply shake them gently in the old tank water before cleaning the other media. Sponges and other semi-durable media should be rinsed thoroughly in the water from the canister. Discard the dirty filter floss and replace it. This particular tank is peat filtered – the peat is placed in small bags in the middle of the filter, and is changed every few months. Do not wipe off the slime inside the filter, as this is all beneficial bacteria and is necessary for the health of your tank.

Open up your filter canister

Never rinse filter media or equipment in tap water. The chlorine in most municipal water is highly toxic to bacteria – hence the reason it is used to clean water for human consumption. You should always rinse the filter and media in old tank water.

Rinse filter media in tank water, not tap water

Try to clean the filter as quickly as possible to prevent the loss of the beneficial bacteria. After cleaning, fill the filter with tank water and close it up. Leave the filter off while filling the tank so that the chance of getting chlorine/chloramine in the filter is reduced.

Refill the filter with tank water, never tap water

Step 5: Perform other maintenance

This is a good time to clean out dead plant leaves, pick out extra snails, and do other maintenance. Try to minimize the amount of time your hands are in the tank to avoid introducing skin oils and other contaminants.

Remember to clean the filter tube strainer. It often gets clogged with dead leaves and other debris, and should be cleared.

Clogged filter strainer

I take this opportunity to trim plants that are getting too big or thin out the large floating mat of Vallisneria spp. that my large pleco creates when he tears up the beds. The debris from the tank makes a great addition to my compost pile!

Step 6: Refill the tank

Get all of your chemicals together. Use a good dechlorinator which is effective against chlorine, chloramine, and heavy metals. Getting one that also replaces slime coats or adds bacteria is entirely optional – I’ve never cared for them myself, but it’s all a matter of personal preference and you should use the one you like best.

Refill the tank slowly

Grab your thermometer and start the tap water. Turn on the hot water and let it get good and hot. Then turn it way down and turn on the cold water. Run water over the thermometer and adjust the temperature until it is identical to the tank’s temperature. After a while, you will get good at feeling the proper temperature with your hand and the process will go faster.

Adjust the water temperature carefully using a good quality thermometer

Start the water flowing back to the tank. Be sure to measure the dechlorinator carefully and add it gently to the stream of incoming water a little at a time. Keep an eye on the temperature of the incoming water, as many faucets have a tendency to creep up in temperature over time.

This is a good time to add any other chemicals that may be necessary. My blackwater tank requires both a water softener and blackwater extract in addition to the peat filtration because the water here in Colorado is very hard. I scoop a little tank water into a dedicated aquarium cup and add the softener to it. Then, I swirl it until all of the softener dissolves and add it slowly to the stream of incoming water. This prevents pockets of concentrated chemicals and ensures the fish don’t try to eat the grains as they fall. This method can be used for any chemical you need to add.

When the tank is full, switch off the water and restart the filter. Make sure it is going well before walking away. It is sometimes necessary to prime the filter or ‘burp’ it a little before the flow will return to normal.

A clean tank is a happy tank

It is entirely normal for bubbles to accumulate on the walls of the tank or float around for a while after a water change. They will dissipate in a couple of hours on their own.

Test the water if you adjust the pH or any other parameter while filling the tank. If it is not the same as before you started, then add a small amount of chemical and let the filter run for about an hour before testing again and continuing adjustments.

Step 7: Don’t forget to reward yourself for a job well done!

Yum!