I have been keeping fish for many years and it seems that in the last few months I have had several fish dying in my tropical tank. My water seems ok with correct pH, no ammonia or nitrite, it’s not overpopulated and I do weekly water changes and have a big filter but they are still dying. Many of them look totally ok then they are dead the next day. What can I do?

Brendan Jarvis

This problem is becoming very common, I get people asking me this all the time. This will just be because your kH level is zero. It is very important to increase the kH every time you add new water to any fresh water aquarium. Carbonate (kH) is an essential element to all biological life and you will continue to have one problem after another until you fix it. To increase the kH simply add a buffer morning and night till your kH level is at least 80ppm. This will ensure your fish live a long and happy life.

Good luck and enjoy.
Paul Talbot


I was worried how long my tank could last without power?

Russell Frank James Sullivan

That will depend on how many fish you have and how big they are. It is a very good idea to have a battery-operated air pump on hand just in case if this ever happens as lack of oxygen is the main problem when power is out. The more fish you have and the larger they are, the more oxygen they need. Most heavily populated tanks will last about 6 hours but can last several days with a battery-powered air pump. Don’t feed the fish if the power is out and introduce a double dose of water ager every few hours if possible. Large animals like sharks consume massive amounts of oxygen so having a back-up plan is very important for them.

Good luck and enjoy.
Paul Talbot


I keep getting algae in my Marine tank and no matter what I do it keeps growing. What can I do now I have tried everything?

Joel Davis

Solving algae problems is very simple. Make sure your phosphate level is zero using a phosphate removing sponge and 3 weeks after it is zero the algae will start to die. Keep it at zero and about 3 weeks after that it will be gone. It is never more complicated then that as algae needs phosphate to live.

Good luck and enjoy.
Paul Talbot


I have a heavily populated Marine tank with all the best equipment including a UV sterilizer but I keep getting White Spot on my fish and they keep dying. I only buy a couple of fish a week from good shops and it is a very big tank with perfect water quality. How can I stop this?

Wayne Trinder

It is important to ensure that your aquarium is running perfectly for one month before you ever introduce new fish to your tank. When the aquarium is running well for a month, it will be stable and all your fish will have good immune systems. When the new fish are introduced their immune system is low due to the stress of the move. While the immune system is low the fish have an imbalance of pathogens versus antigens therefore there is a high risk of infestation of White Spot disease. When you allow that tank to run perfectly for a month then the dinoflagelate pathogens that infect the fish with White Spot are mostly gone and the risk of contracting the disease is low. Also ensure that your salt level is low (1.020) when you introduce new fish as it eases osmotic stress which also helps to reduce White Spot.

Good luck and enjoy.
Paul Talbot