hello everyone. newbie given reigns of system. help guide me please.

[chad brass]

ok, so... i work in a hydroponics store. the owner got the idea to be the first in the area to setup and run aquaponics in the shop. great idea in theory.... but none of us know what we are doing. i have a background in fish keeping and breeding, and obviously with plants so i took the head of the operation.

heres what we have, aero flow 60 http://www.hydroponics.net/i/211145

kept the stock pump to run the aero table and added auto top off and a pump to circulate the system, boss says it has a turn over of once an hour, does this need to increase?

the water flows from the aero rez to the fish tank, a 250 gallon holding tank with 50 tilapia fingerlings and a pleco.

the holding tank overflows into the 40 gal bio filter and returns to the aeroflow 60.

[URL=http://imgur.com/RCnlU][IMG]http://i.imgur.com/RCnlU.jpg[/IMG][/URL]

i knew enough to cycle the tank and make sure nitrites were 0 and ph was like 6.5 temp around 69

we had an issue right away, they ordered the fish and when they arrived we realized that we needed to adjust the systems ph but could not use anything we had on hand since it all had citric acid. we make our own ph adjusters for hydro systems so we just used 86% phosphoric acid.

anyway, this fish are in and have made it through what i consider to be the crucial 48 hours that tell me if they are going to live or not. they have.

[Bob Campbell]

It looks like a great system, but you are still thinking in terms of keeping fish and doing hydroponics, and slightly missing the point of aquaponics by having a separate biofilter that is not growing something.   Nothing wrong with this, but it's not quite utilizing the full advantage of aquaponics. 

If you were to replace the biofilter with a 3/4" gravel bed or something like Hydroton you would be filtering the debris, creating a place for nitrification to occur and have more area for the plants.   Next add some worms and you will have a self sustaining low maintenance system.

[chad brass]

but as it sits, you think its a suitable system?

i got put at the head of this thing and i just dont want to fail. i worked hard to get this job and i intend on keeping it.

[Bob Campbell]

Yes it will deliver Nitrates to the NFT (Nutrient Film Technique) bed.  

In the past my logic has been questioned when I've suggested supplementing Ammonia,  but you have 50 fingerlings which may not  produce enough Nitrates until they grow a little larger and begin to eat more.  I have not encountered any problems when I supplemented ammonia, but you must keep an eye on the nitrification when you do this so you don't kill the fish.  But it appears you are keeping a good log, and testing the water often.  As long as your Nitrates are above zero you will be fine.

Keep your water very clean.  Hydroponics is not as prone to sludge which will suffocate the roots.  I expect your bio-filter is a good design, and so you should not have any problem, but the roots should be white not brown. 

Your pH is good. I can't tell from the picture what you are growing, but a little chelated iron would not hurt.   Some plants begin to turn yellow when the iron is too low. 

I like to use  Dr. Iron.   Don't use MicrobeLift Iron Chelate.  It's for aquariums, and not strong enough.   Iron may turn your water brown, but it's not going to hurt anything. 

Depending on the plants, the temperature might be better just  a little bit higher at about 72F.  

Phosphoric acid is often used in aquariums and it is OK,  but hydrochloric acid (Muriatic pool acid) is preferred by most aquaponist.  It's probably no big deal and probably not something you sell at the store.

I have had trouble with NFT systems in the past and prefer DWC because NFT is susceptible to the room room temperature changing the water temperature.. 

[chad brass]

thanks bob! great tips here. 

i keep a daily log of water parameters: PH alkalinity nitrite nitrate temp ammonia and TDS.

i agree that the temp should be a bit higher but we have a little trouble getting the OK on equipment for systems that the boss himself did think of. (one of those "if it isnt my idea, its a stupid one" kind of guys....) but im trying to get the ok on a couple water heaters we have on the shelf.

the plants are chocolate basil, and the damage you see is actually onion thrips, being a hydro shop, we constantly have pest issues.....silently the real name of the game. 

pretty much the same deal with the phosphoric acid instead of hydrochloric acid... i recommended the hydrochloric and he brought phosphoric, probably just because its what i asked for lol.

again, i thank you for your input, puts my mind at ease that i wont come back from the holidays to them all belly up and a stinky store lol.

happy holidays