4 month old system seems lacking nitrogen

[Roland]

I have a CHOP 2 system set up based on a 65 gallon tank and 30 gallon sump and feeding a 4 cubic foot grow bed under 250 watts of T5 fluorescent lights. I have probably 25 small goldfish and two large (5") goldfish plus some algae eaters. I have a tee in the main water supply line from the sump which allows water to circulate into the tank (seems good for the fish and the idea was that it would help to reduce resistance on my pump), it then carries on up to the grow bed. So my medium is Grow Stones, and I have herbs planted in the grow bed. Can anyone suggest why my basil and mint are looking light green and perhaps lacking nitrogen? Is the tee into the tank somehow stealing my nutrients before the water makes it to the grow bed? I just added some red wigglers the other day in hopes that this will help with added nutrient up take and minerals.
Any suggestions? Am I lacking fish? By the ratios, I am circulating my tank every hour and I have a bell siphon.
This is my first time on this forum and I am excited to share knowledge. This is my 4th aqauponics build so far and I have big plans! Any ideas would be appreciated.
Roland

[Roland]

Ok I'm going to test the nitrates this morning. The basil is yellow in its stems and leafs. The mint seems to be much greener, and the parsley has some yellow leaves. I will post the results after I do the test. Thanks for the advice!

[Alex Veidel]

Did the yellowing start in the older leaves or the newer ones?

Roland said:

Ok I'm going to test the nitrates this morning. The basil is yellow in its stems and leafs. The mint seems to be much greener, and the parsley has some yellow leaves. I will post the results after I do the test. Thanks for the advice!

[Roland]

Tested the nitrates this morning and they were very low. I bought some pH down from the pet store, going to add it to the tank tonight and then test pH again over the next while. Not sure if it matters, but I introduced the basil as a full size living plant from the grocery store. I gently removed the soil from the root bulb and then planted them into my Grow stones medium. I also did this with the mint, parsley and thyme from the grocery store. I am remembering from a previous system that Thyme does not do well in aquaponics (too much water for the roots I guess). Will be adding lettuce, Swiss chard, cayenne peppers, and a few sword beans that I have germinating in soil.

[Chris Griggs]

I would bet your iron is low too. Do you have a grow store or nursery nearby?? I would add a small amount of blood meal just to boost it a lil and add some chelated iron. I would bet money that would clear it up for a bit.

[Roland]

Hi guys
So I found out that my water is very hard (+280) according to the GH test I did. Also, I added pH down liquid today in the morning, and then checked it this afternoon. The pH is at 8.7, which I know is too high for my grow bed. I am planning on adding the pH down liquid again tomorrow morning. Does anyone know if Grow stones messes with pH? The website says it is inert, but Sylvia doesn't recommend it due to cost and what she believes will be a problem over time with the medium breaking down into grains of glass. Has anyone successfully used this medium in aquaponics? Any suggestions?

[Rob Nash]

first off... Love the Alex Grey pic,, that's my desktop picture on my pc right now.

with the high pH, your nutes are a little locked up, just add iron and mag till its at the correct levels (2.5 and 50)

leave the pH high.,.. you want to establish bacteria first, they like it high.. in fact all of the adjustments is mores stressful than leaving incorrect.

growstones work fine in ap .. they do crush down a bit after a while.. don't sweat it.
but should not be effecting your pH..

if you leave the pH high for now, it will allow the bacteria to establish faster and thus your pH will drop on its own once your system goes acidic..
then you will want to add some river rock to the media... instead of trying to raise you pH.

trust me on this one,, I haven't adjusted pH in 3-4 years

[Chris Griggs]

Are the growstones Haydite?? (Expanded shale?) I have hydrocorn (expanded clay) in 2 beds and haydite in 2 others. Got the haydite for FREE from factory! Have had zero issues and good luck with both.

[Roland]

Hey thanks Guys!
Rob, when you say add iron and magnesium, are you saying that this comes in a liquid and I should add it to the tank or sump water?
For Chris, growstones are made of recycled glass which is why I chose it, as I feel it is environmentally less of an impact than expanded clay pellets which are mined.

[Chris Griggs]

I see. They still have plenty of surface area and porasity for they bacteria? My first unit came with the clay pellets and didn't like the cost on my second one. I found the haydite and have used it since. Its a waste product from a local factory so I am saving them from trucking it back to be reprocessed and resold + I get free media. I'll take it....

[Arthur King, Jr.]

Roland, Just my two cents.  My system was at a high pH for several weeks when it was cycling and now stabilizes around 6.6-6.8.  I too have very hard water.  I would watch adding pH Down from Pet stores as some of what they sell has sodium in it.  I had to order mine online as I could not get the pH Down for Hydroponics locally.  Even when I added it, it only held the pH down for a day or 2 and then it would go back up.  I think you will be fine once you bacterial are established.

[Roland]

Thanks Arthur King Jr.!
I appreciate your two cents:)

[Alex Veidel]

Roland, magnesium is commonly added in the form of magnesium sulfate (epsom salt), which can be added to your water, or used as a foliar spray on your plants. Iron-chelate is used to supplement iron (which also is added to your system water).

http://www.theaquaponicstore.com/AquaIron-DTPA-Iron-Chelate-p/agsas...

Roland said:

Hey thanks Guys!
Rob, when you say add iron and magnesium, are you saying that this comes in a liquid and I should add it to the tank or sump water?
For Chris, growstones are made of recycled glass which is why I chose it, as I feel it is environmentally less of an impact than expanded clay pellets which are mined.