Plant PPMs & Nh3/Nh4 PPMs

[wh33t]

If you use an electric pH meter you have to calibrate it frequently with solutions of 4,0 & 7.0. Don't use litmass paper it is easily fouled with humidity. The ppm is used exclusively in hydroponics to measure nutrient levels. Primarily ppm of. Nutrients/minerals. And also used to measurer hardness of water. The ppm can then be converted to the German scale of DH. The try meter you have (I have one also) was compiled to measure the hydroponics parameters. With all of the suspended organics from aquaponics I do not use it as a system monitor for AP.

Yes, I have calibrated it many times. Also you should only use PH Calibration solution of 4 if you are expecting PH results lower than 7. For AP I think I'm going to use the PH 10 Calibration solution as it's pretty rare to have a PH of less than 7 in AP no?

[urbanfarmer]

How long can I go with out feeding the fish?

A week or two.

it's pretty rare to have a PH of less than 7 in AP no?

It's pretty common, and what is commonly accepted as a "good" pH for an AP system is 5.5 - 6.5.

[rfeiller]

depends on the condition of the fish if they are in good healthy full bodied then a few days will not kill them, but if they were feeders that you purchsed they are probably not in that great of condition. can't help it i've worked with too many fish. today when you buy the fish from places like petco and petsmart the fish are seldom in good condition.
since the nitrifying bacteria tend to attach themselves to an object including the sides of the container they will continue to multiply just as effectively with the water changes as without, the difference being the condition of the fish. gotta put in a plug for the fish. by the way plants do a fair job of obsorbing ammonia.

[wh33t]

depends on the condition of the fish if they are in good healthy full bodied then a few days will not kill them, but if they were feeders that you purchsed they are probably not in that great of condition. can't help it i've worked with too many fish. today when you buy the fish from places like petco and petsmart the fish are seldom in good condition.
since the nitrifying bacteria tend to attach themselves to an object including the sides of the container they will continue to multiply just as effectively with the water changes as without, the difference being the condition of the fish. gotta put in a plug for the fish. by the way plants do a fair job of obsorbing ammonia.

Does the Ammonia hurt the plants? Good to know the fish can go a while with out food. I'm gonna go 48 hours and see how it is.

[urbanfarmer]

The plants will start absorbing more ammonia over a pH of 7. At a pH of 8 they will take up a good bit of ammonia. Pet stores do not take good care of feeder fish. Recently, I saw a tank of feeders all going belly up because of the lack of care at my local Co Pet store... anyway, 48 hours won't be a problem since you've been taking care of them for a while.

[rfeiller]

yes i have actually found that plants do a wonderful job of utilizing ammonia, contrary to everything i have read.

[urbanfarmer]

You are reading the wrong stuff! Plants only need to use 5 ATP to absorb ammonia, but they need to use 15 ATP to absorb nitrate. In other words, plants are 300% more efficient at absorbing ammonia.

[rfeiller]

story of my life.

i have removed the 100gal res. and replaced them with 30-90gal aquariums. on one system with a 30gal tank with only(8)-2-3" gold fish feeding a fully planted 4'x4' grow tray the nitrates went above 40ppm (if you can believe api regents) so i removed the goldfish for over a week and saw no noticeable reduction in nitrates. i believe the plants are actually growing off of the ammonia. i was trying to determine at what point the plants actually "purified" (using that term very loosely) the water. or at least kept up with the production of nitrates. i feed the fish heavly to get growth out of them and to condition them to breed.
i can take an oscar (not from petco or petsmart but from a reputable breeder) condition it to a force feeding regimen and it will be over 12" and breeding in 6 months. as commercial breeders we do this with most species of fish. time is money.

in my own experiments using aquatic plants they seemed to utilized the ammonia first, nitrites second, and almost no nitrates.
in my commercial discus hatchery most of the tanks had a 50% water change daily. zero nitrates, zero ammonia and the amazon sword plants were huge. they absorbed the ammonia as fast as it was being produced by the fish. the breeders and young fry tanks were not on a central system.

i believe once i get it dialed in i will not have any nitrifying beds and will perform water changes to maintain almost zero ammonia & nitrates. i realize that one of the selling points is to save the water, by recirculating it. i'll use it on the 70 rose bushes.

[urbanfarmer]

WOW, those are some amazing results. Do you recall what the pH was by chance? Usually, ammonium uptake is good at over a pH of 7.

[rfeiller]

also contrary to a lot of beliefs about varying pH with fish depending on what i was doing with them the pH could have been as low as 4.0 or as high as 7.6. where the stress on the fish comes about is with the polution in the water. if the water is clean you can move them around from high to low or low to high pH without causing any harm to them. on a closed system i would NEVER vary the water's ph quickly. the reason for the pH changes could be to stimulate spawning by lowering the pH or to raising the pH to put the fish in a breeding rest cycle. a pH of 4 would be to stop bacteria or viral infections without meds. the plants were not removed from the aquarium regardless of pH. the water could have been pure RO with a rejection rate of 99.75% to full tap water 400ppm hardness with total alkalinity of 150ppm and a ph of 7.6. i only use GAC to remove chlormines in the hatchery. because of disease control, i always used lab nitrifiying bacteria to innoculate any system. i stopped using salt for any purpose when it proved basically worthless. (this of course would not be the case with fish that are accustomed to brackish water or with a high alkiline water such as africans from the rift river system, or several species of livebearers. if you want beautiful sailfin mollies go to saltin sea in so. CA.
excuse me for rambling, but there is seldom a one word answer.