Map showing City of Fresno blend of surface water us and groundwater use prior to additional water supplies from the Southeast Surface Water Treatment Plant

City of Fresno’s Historic Change in Water Source Affects Aquarium pH

by Tom Lang

Since 1980, Aquarius Aquarium has been maintaining aquariums for clients throughout the City of Fresno (and beyond).  It was a tremendous advantage to be able to change water as a part of our routine and have the pH of our client remain fairly constant between our regular service visits. Most of our clients have us out either monthly or every-other-week, so water chemistry did not vary very much from what came out of the tap.

Historically, the City of Fresno sourced all its water from a network of wells located throughout the city. Giant electric pumps brought up water from the vast aquifer located beneath the city that contains a significant level of carbonate hardness (KH – from the German Karbonathärte – also known as Alkalinity) because the San Joaquin Valley was a great inland sea millions of years ago. The calcium carbonate skeletons of marine organisms are still found in layers far below the land’s surface to this day and, as water has seeped down through these layers over millennia, it picked up carbonates and bicarbonates by dissolving those deposits along its way.

Over many years, our tests routinely measured tap water KH in Fresno in the 8 -10 dKH range when the water was sourced from groundwater. But since 2018 and 2019, the city has introduced more and more treated surface water from the San Joaquin and Kings Rivers into its system. The Southeast Surface Water Treatment Facility (SESWTF) completed construction in 2018 and is being fed with surface water from the Kings River through a newly-constructed 13-mile long Kings River Pipeline.

Soon after the SESWTF came online, our testing indicated a marked decrease in KH readings in nearly all areas of Fresno, bottoming out during the summer of 2019 with some taps testing as low as 1 – 2 dKH.

What low KH means to aquarium owners

When KH is low, an aquarium water’s ability to buffer against an unsafe drop in pH is diminished when measured over time. As the fish produce acidic waste, the tendency is for pH to decrease over time, effectively “using up” the KH. In most cases when San Joaquin Valley groundwater is the source, low to medium stocked aquariums will maintain healthy pH levels without water changes for at least a month. This holds true in the majority of aquariums as long as KH starts at between 5 and 10 dKH in our experience. However, it needs to be said that this is a moving target and that it follows that more fish in any given aquarium will speed up the process of “using up” KH.

While the city will truthfully say our water complies with federal EPA standards, these standards do not specifically take into account how much KH is present in our tap water. The City of Fresno’s own “Recharge Fresno” website made it clear that as more surface water is added to the system, the lower its alkalinity will be. This is due to water from mountain snow run-off contains significant less KH since this water has not seeped down through the San Joaquin Valley floor’s calcium carbonate sediments.

20 gallon aquarium with large plant

Apartment Aquariums

by Tom Lang

An apartment aquarium is a great pet for busy people who just don’t have time for a dog or a cat. Most apartment managers are fine with a small aquarium in rental units, but don’t assume small means mini. A good apartment aquarium size to start with is a 20 gallon (24”long x 13”wide x 17”tall). This size can accommodate a nice selection of freshwater tropical fish and even live plants.

20 gallon aquarium with large plantWhether you buy your set-up from a local fish store or through Aquarius Aquarium, Inc., our professional aquarists will help you get it going and then maintain it for you on a monthly basis.

We generally recommend many small, colorful community fish for a 20 gallon aquarium such as tetras, rasboras, danios, gouramis and maybe even


one angelfish (don’t try two angelfish or you are likely to have one ending up being dominant, causing the other one to die). Some of our clients have gotten away with six or more angelfish for months, but compatibility issues usually develop as these not-so-angelic fish mature.

Popular bottom fish for a

20 gallon aquarium are corydoras catfish that come in a variety of colors and patterns. These catfish do a nice job keeping the bottom clean of extra food the other fish may miss. We do not recommend a plecostomus or other potentially large bottom fish as these take up too much tank space very quickly and produce copious amounts of waste.

Easy-to-grow live plants such as an Amazon sword, Anubias or Java fern will do well in a 20 gallon aquarium with about 8 hours of light a day. We have been impressed with the growth of these varieties under the white LED lights that come with even the most budget-friendly options combination kits. Some other aquatic or semi-aquatic plant species offered for sale do not fare as well in aquariums without specialty lighting, regular fertilizer additions or CO2 supplementation. Of course, if you’re interested in a high-end planted aquarium with more challenging species, we’d be happy to discuss the options available.

With all the choices out there, we understand that putting an apartment aquarium together can seem daunting, but that’s what we’re here for! Contact us today and we’ll walk you through the process so you can enjoy the beauty of this slice of nature.

More Fish = More Service

by Tom Lang

One of the most common requests we receive from our clients is that they want more fish for their aquariums. While we would like to make a sale or see a tank absolutely chock-full of fish of all types and colors, we are often put in the position of having to explain why more fish will require more service. Hopefully this article will explain why this is the case.

We all know that our fish pets produce waste. We just don’t usually see it like we would if we had a cat or a dog or a horse. But think about that for a moment. The larger the animal, the more waste produced requiring cleaning of the litter box, yard or stall. The same goes with quantities – two cats, three dogs and a stable of horses all create more work for us than one individual animal.

All of this might seem obvious, but it is the same with fish in an aquarium. Let’s say you have a good-sized tank with a dozen small to medium-sized fish and things are going along just fine with once-a-month water change, cleaning of the filter, etc., except that you would prefer to see twice the number of fish swimming in the aquarium.

With double the fish, the amount of waste that will need to be processed by the nitrifying bacteria living in your aquarium will be doubled. These bacteria are essential to the success of every aquarium and work to transform fish waste into nitrate through the nitrogen cycle. Nitrate will therefore be produced twice as fast and in twice the quantity when the fish population is doubled. Since nitrate is acidic, an increase in nitrate will cause a more rapid, unsafe drop in pH, endangering the lives of the fish.

Now, taking into account that young, small to medium-sized fish are usually the ones selected to go into a new aquarium, it is important to also consider the potential adult size of these animals. A small fish may stay small if that is the normal size for that particular species, or a small fish may, in a few short months, grow into a large, or even extra-large fish ten to twenty times the size of when it was first introduced.

Rather than focusing on the quantity of fish in an aquarium, it is always more helpful to focus on the total combined mass of all the fish fish within a given tank. We have some clients with one extra-large fish in a medium-sized aquarium and that is truly equal to having twelve to fifteen small fish in that same tank.

The point of all this is that the waste produced by a heavily-stocked aquarium will far exceed what is produced by a lightly-stocked aquarium and will require more water changes, more filter cleanings and more over-all attention to the system. Pushing the limits of what any given tank can support also means that the entire population is close to the tipping point for a tank crash if one or two deaths go unnoticed. Dead fish remaining in an aquarium even for just a few hours can rob enough oxygen from the water to cause all the other fish to die.

Heavily-stocked aquariums require attention multiple times a day accounting for each and every fish, very precise feeding since decomposing extra food can also rob oxygen from the water and scrupulously cleaned filter media and components. Offices that are closed on weekends or over long holidays run the risk of coming in on Monday morning to a tankful of smelly dead fish because it always seems to be that a fish will die on a Friday evening after everyone has gone home.

A light to medium stocking level gives all the fish a much better chance for long-term survival should the inevitable challenges inherent with all aquariums occur. A power outage will not immediately wipe out a lightly-stocked tank. A pump failure will not mean quick death in an aquarium with a dozen fish versus two dozen fish.

We encourage all our clients to stock lightly and succeed with once-a-month service visits. We are always happy to increase service frequency to accommodate medium stocking levels as well. But even with increased service levels, the more fish that are in any given aquarium, the more we need our clients to be partners in accounting for all their fish on a daily basis and to call us immediately if anything out of the ordinary is observed with the fish, the water clarity or the filter system operation before a small issue turns into a major problem.

Water Softener Woes

by Tom Lang

We have been seeing more and more homes installing water softeners and then having problems with their aquariums. In order to soften a home’s tap water, many water softeners work by exchanging minerals (mostly calcium and magnesium) with sodium. While this is good for your pipes, shower doors and washing machines, it’s not great for fish.

Aquarium water needs to contain a balance of electrolytes (solutes that break down into ions when dissolved in water) in order for fish to be able to regulate their internal homeostasis. Freshwater fish, especially, require some calcium and magnesium as well as carbonates and other minerals in their water for this osmoregulation since they continuously absorb water into their bodies though their skin and flush it out through dilute urine produced by their efficient kidneys. Electrolytes are lost from the body during urination and if these same ions are not present in the surrounding water, then the fish is unable to achieve internal electrolyte balance rapidly leading to death.

So it is not so much the presence of sodium that causes fish problems in softened water, but rather it’s the lack of calcium and magnesium (measured as GH – general hardness) and carbonates (KH – carbonate hardness or alkalinity) that fish need to survive in an aqueous environment.

In a freshwater planted aquarium, a balance of minerals is also important, however it is interesting to note that plants may do fine for quite a while in softened water even as the fish perish. This is due to a hydrophyte’s (fully submerged aquatic plant) ability to retain minerals in its tissues since, unlike terrestrial plants, it does not need to expend energy retaining water. Calcium and magnesium are considered “secondary” nutrients because plants require these in smaller concentrations than nitrogen, phosphorus, and potassium. Often, aquarists with planted tanks will also add plant nutrients that contain enough calcium, magnesium and other minerals for the plants, but not in enough quantity to provide for the far greater needs of the fish.

Finally, using softened water in a saltwater fish or reef aquarium creates other issues. Again, the lack of calcium and magnesium may require supplementation to bring them back into line with natural seawater. While saltwater fish are drinking seawater rather than absorbing it through their skin like freshwater fish, they still must regulate their internal electrolyte balance. It is necessary to add calcium, magnesium and carbonates to artificial saltwater made with softened water if tests indicate levels below natural seawater.

Fish Store

Pitfalls of Buying Fish from Retail Fish Stores

by Tom Lang

If you’re considering stocking your aquarium with fish and other aquatic life from your local retail fish store (LFS), you should be aware of the risks associated with this practice.

This article isn’t meant to criticize the retail fish industry, but hopefully educate consumers about typical problems encountered when establishing an aquarium.

Even clients of professional aquarium maintenance companies such as Aquarius Aquarium, Inc. often succumb to the temptation of adding “just one more fish” to their established aquatic communities.

Buying a new tank and fish at the same time

It’s always amazing to us to see customers walking out the doors of retail fish stores with a brand new tank and bags of fish in the same shopping cart! A good local fish store will strongly discourage this.

A new aquarium takes time to establish – not just because of the chlorine most municipalities add to their tap water, but also because the nitrogen cycle takes at least several weeks to complete.

This natural beneficial bacterial culture is the key to success in keeping all fish, whether freshwater or saltwater, in a closed environment. If you don’t know how the nitrogen cycle works (or how to test for it) then you should not be purchasing fish until you do.

For all new aquariums installed by Aquarius Aquarium, Inc., we carefully monitor critical water quality parameters frequently during the early weeks when adding new fish.

Once an aquarium is established, it is not as critical to constantly test the water, but many problems can be prevented by paying regular attention to the basic parameters. Taking appropriate corrective action when such action is warranted by testing can save not only the cost, but also the lives of your new fish.

Introducing disease to your new or established aquarium

Click on this photo to see if you can you spot signs of disease on these beautiful saltwater fish offered for sale at a local fish store.

Whether you have a new aquarium or a long-established community, the number one cause of disease being introduced to your aquarium is through the addition of new fish, living plants, corals or any other aquatic life. Retail fish stores receive frequent deliveries of fish, often from multiple sources.

The busiest stores can bring in multiple shipments in a week with an accompanying high turnover of fish in their sales tanks. These are the stores that gain a reputation for their “great selection,” which in turn attracts many customers!

The main problem with this is that even one newly-arrived diseased fish can infect all the other fish in its tank even if these other fish have been disease-free up to the day of the arrival of the sick one.

Add to this the common practice of linking all the tanks in a store together on one master plumbing system, and it is very likely that a disease can run through an entire section of interconnected tanks.

Free-swimming stages of parasites, viruses, bacteria and fungi can easily travel through the pipes from tank-to-tank and the water going home with an unsuspecting customer can be teeming with microscopic disease agents even if the fish in the bag appears completely healthy.

Buyer beware and the benefits of quarantine

So, how can you avoid the pitfalls of buying fish at your local fish store (LFS)? There are a couple of ways.

First, consider buying your fish through a local aquarium service company like Aquarius Aquarium, Inc. that is committed to only selling fish after quarantining them for a period of at least two weeks.

But if you still wish to purchase your fish at a LFS, be very sure that the fish you are considering adding to your aquarium is in good health. If the fish exhibits obvious signs of distress (rapid breathing or mad dashing around the tank), damage (torn fins. missing scales) or disease (cloudy eyes, fungus-like growths, or tiny white spots that look like salt stuck to the fish) you should not buy that fish, no matter how tempting it may be to try to “save” it or what discount the store offers you.

Also, if after asking a store staff member to feed the fish, the fish is not eating, do not buy that fish. When a fish isn’t eating in the store tank, it is unlikely it will in your tank.

Finally, if the fish appears healthy and is actively feeding, you can contract with a local aquarium service company like Aquarius Aquarium, Inc. to quarantine your new purchase for you or you can set up your own quarantine aquarium.

Keep in mind that any quarantine tank must also have a fully established biological filter just like any aquarium before you purchase your new fish or fishes. If not, you will encounter the same problems as those customers who buy their new aquarium and fish on the same day.