The Indoor Aquarium Aquaponics Frequently Asked Questions is created by both people asking questions on this website as well as reviewing the search engine search queries. The answers here will be brief and specific to indoor aquaponics and most will link to more details.

How to turn an aquarium into a hydroponics system?

By making an aquaponics system! You’ve come to the right website. Feel free to browse this site and learn how to create an aquaponics system using your aquarium.


Carbon Filtering

Can I use activated carbon on aquaponics?

Related Questions:

  • removing carbon filter fertilizing plants

Short answer, no. The activated carbon will remove many ionic micro-nutrients the plants needs to grow. The long answer is ‘maybe’. Read More

Does activated charcoal filter out the good bacteria in an aquarium?

No. The bacteria need to live on something, they don’t just float about in the water.

Activated Charcoal (activated carbon) is both very porous and attracts both negative and positive ions in the water. It’s good at removing heavy metal ions, clorine, many fertilizers & medicines, etc. The only time it will filter out the ‘good bacteria’ is when you change the charcoal. If the charcoal has a filmy slimy surface, the bacteria have actually colonized the charcoal and by changing it, you are removing the bacteria colonies. Many filters have a sponge or something that doesn’t get changed that the bacteria can colonize and not get discarded with the charcoal change.

Is activated carbon bad for fish?

No, it’s not bad for your fish. A great many commercial aquarium filters depend on activated carbon to keep the fish tank water crystal clear and smell free. It can be a problem with your plants.

Is it safe to move your carbon filter to a new tank?

Probably, if your existing tank was healthy. I quite frequently use an existing, established filter to ‘speed cycle’ a new aquarium.

Should I leave foam filter in aquaponics system?

Yes. The foam filter contains the ‘good’ bacteria colonies. Running your regular aquarium filter in an aquaponics system gives you a bit of redundancy. It also allows you to add aquaponics to your existing aquarium without worrying about needing to re-cycle your tank. Read More

Is poop on an aquaponics growbed good or bad?

It depends. For indoor systems, probably not a lot. The breaking down of the ‘poop’ creates ammonia, which can be some pretty potent smelling stuff. The plants love it, of course. On many larger, outdoor systems, they add a few earthworms to deal with the ‘solids’ in the growbed – do a web search for ‘aquaponics vermiculture’. You can also build a simple solids pre-filter and then you would only need to clean the pre-filter. Read More

Can I use a bigger filter in a small aquarium?

Related Questions:

  • Is it bad to over filter aquarium?

Yes, as long as the filter isn’t so powerful that it creates water currents in your tank so strong that it stresses your fish. Fish from lakes and ponds may not appreciate the fast moving stream environment you re-created with your massive filter. I like to use 2 different types of filters that are both rated for at least the aquarium size if not a little bit more. That way if one fails, the other is more than capable of picking up the slack.

Aquarium water pump won’t prime.

Many Aquarium water pumps are magnetically driven. Sometimes gunk or a small rock gets in the impeller and the pump seems like it’s working but it’s not. The pump should pull apart around the water intake housing. Clean the impeller and that space.

Next try to poor some water into the outlet of the pump. This often will help the pump clear itself of any air-bubbles that may be preventing it from priming. If the pump is trying to lift water higher than it’s rated for, it won’t prime.

Do I need to worry about the rise in pH starting a new tank?

Related Questions:

  • Does pH rise and fall in new aquarium set up?

Yes and no. This is part of why it’s recommended to use hardy fish to cycle your system. The first few weeks the water chemistry is going to be all over the place. As long as the pH is within the safe range – even if it’s hovering near ‘bad’ it may be better to leave it alone for another day and see what it does. As the tank begins to cycle and as the ammonia is converted into nitrites and nitrates, the PH tends to fall over time. If you can keep the pH between say 6.5 and 7.5 or so, it should be ok in most instances. The fish in your system may not like such a low or high extreme.


Would adding salt in an aquaponic system be bad?

Some salt, yes, a lot, probably not – it depends on your plants. Aquarium salt is a great general tonic for many fresh water fish. However,  many plants are not very salt tolerant. It may be safer to move your fish to a hospital tank for any serious salt treatment than to risk your plants health by adding salt to the aquaponics system. Read More

Can hydroponics fertilizers be used in aquarium?

Some can. Many hyrdoponics fertilizers are mineral salts and fish are ok with some of these, and not others. Watch out for hydroponics fertilizers that contain sodium as that can accumulate in the tank and cause problems. Most organic additives such as sea-weed extract should be OK to use.

How to get chlorine out of water for an aquaponics system?

Related Questions:

  • Remove chlorine in hydroponics?

The safest, cheapest, laziest way is to simply let the water sit for a while in an open top container. Allowing water to ‘age’ in a bucket (that has never had soap in it) for a couple of days will allow the chlorine to naturally outgas from the water. The more water surface area or agitation (air bubbler) will speed things up. Read More

Grow Beds

Help, my aquaponics bell siphon won’t autoflush.

Bell siphons can be fussy to get set up and balanced right. You have to balance the size to the amount of water coming into the growbed. If the siphon is too big or the water flow too low, it won’t get a good start. If the siphon is too small or the water flow to much, it won’t stop (‘break’) the siphon. Adding bends to the drain pipe can help start a siphon while adding a small hole in the bell can help the siphon ‘burp’ air and break. Read More

Using a powerhead as an aquaponic pump

Aquarium Powerheads are designed to move a lot of water at the water surface level. They aren’t designed to ‘lift’ water. For a small indoor system where the growbed isn’t more than a foot or two higher than the aquarium water level and your not using a sump, the power-head may work ok. Try it and see if you get satisfactory results.


Can you add more fish after 1 month to a new tank?

Yes. You should add very few fish at first, and add more fish later as the aquarium  ‘cycles’ (filter able to handle fish waste). The best way to add more fish is to use a quarantine tank and to examine the fish at the store and see if they are healthy before you buy them. Clamped fins and rapid breathing at the top of the tank or the gill area extra red are not good signs. Read More