Comments for Aquaponic Lynx LLC

Comment on Basic Media Bed Aquaponic Design by r dondero sr

r dondero sr — Wed, 15 May 2013 05:03:56 +0000

ok when i get more grow media i will adjust to keep top portion dry thank you

Comment on Basic Media Bed Aquaponic Design by TCLynx

TCLynx — Wed, 15 May 2013 02:43:04 +0000

Hum, so is 8″ of media enough? Hard for me to say since I don’t know how heavily you will be feeding the fish or how many fish (as in I don’t know how much filtration you NEED.) But as long as you are not growing corn, tomatoes and bananas in the tote, you will probably be ok with the shallow grow bed media depth. Just make sure you keep your flood height well below the top of the media (you want the top of your media to stay dry for the most part.)

It is fine to have a little water remain in the bottom of the grow bed between flood cycles.

Comment on Basic Media Bed Aquaponic Design by r dondero sr

r dondero sr — Wed, 15 May 2013 01:06:55 +0000

thanks for your answer i have 4 inches depth of grow bed media in a 19 gallon tote.if i add another 4 inches of depth is that suffecient,? also does the water need to drain dry or can some still lay in bottom like maybe 1/8 of a inch?only way i could get it real dry is poke some small holes to drain into fish tank. i don t have a sump tank only the fish tank and grow bed. i have it set so it pumps about 5 gallons into grow bed,from 20 gallon fish tank, i dont want to stress the fish

Comment on Basic Media Bed Aquaponic Design by TCLynx

TCLynx — Mon, 13 May 2013 01:45:20 +0000

How big is the grow bed? Only 4 cubic inches? or is that 4 inches of media depth? or is the grow bed 4 inches by 4 inches with 4 inches of media in it? How many fish are you going to have in your system? Will your system have a sump tank? If you are simply pumping from your fish tank up to the media bed and having the media bed flood and drain back to the fish tank, you can only really have about 20 gallons of grow bed total to keep the fish tank from fluctuating too much, it will fluctuate if you do flood and drain. Only 4" of media depth is a bit shallow for larger plants, what sort of plants do you want to grow? How deep is the bed? 12 inch deep grow beds are often recommended since it gives you lots of filtration while providing plenty of space for plant roots. Many people manage systems with shallower media beds but you have to be careful of large plant roots clogging the beds. I'm working on a book that might be of interest Aquaponics in a Nutshell

Comment on Basic Media Bed Aquaponic Design by r dondero sr

r dondero sr — Mon, 13 May 2013 01:37:52 +0000

i have a 20 galon fish tank how many inches of media do i need in the growbed? right now i have only 4 inches .if i add another 4 inches is that enough?

Comment on How to Size Your Sump Tank by Ron Schreiber

Ron Schreiber — Thu, 09 May 2013 21:31:42 +0000

thsi is very helpful . just starting out in Aquaponics ..I like it alot …

Comment on Channel Catfish by TCLynx

TCLynx — Mon, 06 May 2013 13:19:22 +0000

I don’t think there is really a good answer for “Ideal pH and nitrate level for a 300 gallon fish tank with catfish”
Catfish seem to do pretty well in a pH range between 6-8 in my experience and nitrates are generally not what is toxic to fish in an aquaponics system, so as long as your nitrates are below say 500, I wouldn’t worry too much about them.

It is the ammonia and nitrite that are probably killing your fish.

Sorry Marry but you are right, you have WAY to many fish for a brand new system. Channel catfish are sensitive to bad ammonia spikes and poor water quality that can often happen in a brand new system, let alone one that has probably well over 3 times as many fish as it should.
Are those 4×8 grow beds media filled grow beds? If so I would estimate that you might support growing out about 32 channel catfish in that system to 1 1/2-2 lb each. (I don’t care if the fish are tiny at the moment, your system isn’t cycled up yet so you should start with tiny fish and only as many of them as you could grow out so the system could cycle up to the load as the fish grow.)
If they are raft beds, do you have any additional filtration? If you are doing a friendly style raft system, I would say you probably shouldn’t grow out more than 10-15 channel catfish in that system.

While the fish are small that system might be able to support more fish but only after it is cycled up. You say you are at 3 weeks, that is normally when the ammonia and nitrite spikes are the worst and it is probably the ammonia and nitrite levels that are killing your fish, not the pH or nitrate.
What do you water tests say.
Temperature
pH
Ammonia
Nitrite
Nitrate

An aquaponics system needs to cycle up (that means have the bio-filter bacteria colonize the system) before it can handle many fish. Cycling up a system usually takes around 6 weeks under good conditions.
cycling up a new system with fish
Aquaponics Fishless cycling
There are some links to blog posts about cycling up a new system.

Channel catfish can handle a fairly wide range of pH (6-9) (the bacteria like a pH of between 7.4-8 and the plants would prefer a pH of around 6 the test kit I have only measures down to 6 so I make sure to keep the pH enough above 6 that I can be sure it isn’t way lower. pH will naturally drop over time so you regularly need to bring it back up but do so carefully since changing it more than about 0.2 per day can hurt your fish, plants and bacteria.) A higher pH is better for getting the bacteria to colonize but if the pH is too high and the ammonia high it makes the ammonia more toxic and tends to kill the fish faster.

Unfortunately at this point the only likely way for you to save fish is to probably get rid of most of them and do lots of water changes to bring the ammonia and nitrite levels back down. Unfortunately if you already have fish dieing, it could be too late and even if you suddenly put them all into prefect water, they may already be weak and have only a limited recovery rate.

Comment on Channel Catfish by mary wood

mary wood — Mon, 06 May 2013 12:58:45 +0000

Can anyone tell me what is ideal ph and nitrate level for 300 gal system with catfish? 150 fingerlins in 300 gal tank and keep losing some each day. We are thinking we have too many fish? Have lowered the 7 air stones to bottom thinking that was problem. Have 2 4 x 8 grow beds. System up only 3 wks now but hate to loose ALL my fish here.

Comment on pH please have patience by TCLynx

TCLynx — Fri, 03 May 2013 02:56:57 +0000

The bacterial action in aquaponics that changes the ammonia and nitrite into the less toxic Nitrate for the plants actually causes the pH to go down over time. This is why we regularly need to add small amounts of buffer to our systems to raise the pH back up and keep it from falling too fast.
I don’t really recommend baking soda since that will add more sodium to your system than your plants want.
For gentle buffers that provide potassium and calcium I would recommend potassium bicarbonate and calcium carbonate. Be sure to only use small quantities at a time since you don’t want to raise your pH much, just keep it from falling below about 6.2. For a stronger way to raise the alkalinity of the water, some people will use potassium and calcium hydroxide. These are very strong caustic substances and can change pH rapidly and need to be handled with care so I don’t usually recommend them for backyard growing.

A simple way many people will add calcium carbonate to their system is to put some shell grit or limestone chips into a mesh bag or some stockings and hang them in the tank. this way if the pH gets too high, you can pull them out for a while till the pH starts to drop again. Potassium bicarbonate can be found a beer and wine making suppliers and can also be used mixed with water to spray on plants to combat certain molds and mildews.

Many people don’t experience the pH drop if they are using hard tap water or well water to fill their systems, they are likely getting lots of calcium carbonate in their water. People who use rain water or have soft water need to keep a closer eye on their system pH.

Comment on pH please have patience by Noel

Noel — Fri, 03 May 2013 02:20:10 +0000

Dear TCLynx,
Just want to know my AP ph keep going down from 7, 6.8,6.4,6. but he fishs still alive an bright. what should i do? still add the Baking soda when its go down? whats makes like this? before everything normal. my AP at the out door, and in HK country side.

thanks a lot