Need advice: Where did my nitrates go?

[Jake Schneider]

Hi Aquanuts!  I have a water issue.  I've been cycling my system for about a month now.  I've had nitrites  at 5ppm and nitrates at 5ppm for the last 2 weeks.  My ph has been hi at 8, I've gotten it down to 6.4 today.  I've been dosing with ammonia every couple of days until it drops to 0ppm.

My plants been showing a lot of yellowing this last week.  My nitrites have dropped to .5ppm and my nitrates have been 0 for the last two days.  So where have my nitrates gone?

I dosed with Maxicrop almost a month ago and the water is starting to clear up.  I've used PHdown to bring my ph down.  I have to top off with about 10 gallons water every 2 days due to a small leak.  I let the top up water bubble with an airstone overnight before adding it.  Am I worried about nothing?

My system has a 300 gal FT, 32 sqare ft grow bed, and a sump.

Any advice would be appreciated.  Thanks! 

[TCLynx]

Sounds like perhaps your plants have used up all the nitrates and if you have much of a leak then it may mean you are sort of doing water changes to keep up with it which is loosing some of the nutrients your plants want.  But it sounds like you are almost cycled up so almost time for fish.

Don't stress too much about it all.  And if you pH is down to 6.4, it sounds like you went too low.  Be prepared to buffer it back up if it drops further.

[Jake Schneider]

Thanks TC!  I wanted to lower my ph pretty low because my top up water runs at 8 or above.  I'm hoping to balance it out.

So I don't need to worry about the yellowing? Its pretty bad with my basil and zucchini.  I'm thinking it may be lockout due to the ph being so high all month.

[Vlad Jovanovic]

Jake, just know that zucchini is a whopper of a nutrient hog...just ridiculous...They need as much potassium as nitrogen, (and they need lots of nitrogen) and about as much magnesium as calcium (which is ALOT compared to most other plants used for food). Most folks think of tomatoes as heavy feeders (which they are) but zucchini/summer squash, cucumbers, just about all cucurbits have them beat by a mile and then some. Try it out, see what happens...but just know that they are the Chevelle 442 of the nitrate (and all other plant essential elements) guzzling world...

Don't go batty in the coming weeks trying to figure out why the older leaves are yellowing (magnesium def) or if the edges of the leaves yellow then turn brown with necrotic lesions appearing all over the broad surface of the leaf (thats just potassium def) or if they seem generally stunted for a zucchini plants (phosphorous def)...it's not the pH (provided your within range) or anything your doing 'wrong'... they are just hogs and your system is brand new and not had time to build up a store of nutrients that feeding the fish for many many months and a good alternating Ca-Mg-K pH buffering regime should provide...

[TCLynx]

If the basil yellowing is starting at the new leaves and the veins stay green, that is iron deficiency or iron lock out.  Some chelated iron will help that and having a lower pH will help too for future.

[Jake Schneider]

Thanks Vlad and TC!  I've been worried about the zucchini.  I think it was iron lock out due to too high ph.  The basil is starting to turn greener already!  I'll be buying some chelated iron, I just didn't think I would need it so soon!  It wasn't just the new growth, but all of the leaves were yellowing, I think I've got it licked for now. 

Thanks for the info on my squash Vlad, I didn't know I had a super charged V-8 chugging all my nitrates!

As all ways, you guys rock!  

[Jake Schneider]

OMG! I'm an idiot! If I was any dumber, they would have to invent new words for my level of stupidity.  All this time, I've been doing to nitrate water test wrong!  Instead of shaking TEST BOTTLE #2 I've been shaking THE TEST TUBE for 30 seconds.  So after running the test correctly, I have nitrates at 40ppm.

The reason I'm an idiot is because I've watched TC's water testing video at least twice and I've read the instructions that came with the test kit, EVERY TIME I've test my water.  I just noticed the wording on the BOLD SENTENCE in the instructions.  sigh   

Thanks for helping, as all ways you guys rock!

[TCLynx]

Jake, you are not the only one who has made an error in the use of the test kits.  I once had some one who was adding all the drops from all the different tests into the same test tube at the same time and couldn't figure out how to read it.

[Jake Schneider]

LOL. That kinda makes me feel better.  But still, to misread the instructions EVERY TIME?  If I ever attend a aquaponics conference, I fully expect to get the DUMB ASS OF THE YEAR award.  And I will accept it graciously .

[TCLynx]

naw Jake, I expect the Dumb Ass awards will mostly go to the people who "normally" know better yet still do something dumb, (Like what I did the other day, I used a flexible coupler on a pressure line to the irrigation.  Luckily I was right there to fully experience the mistake so I could fix it immediately before wasting too much water.  Ya know those flexible couplers are really only meant for non pressurized plumbing because more than a few pounds of pressure will just blow them off the pipes.  I know this and yet I tried using one thinking I'm going to be changing this plumbing next week anyway so maybe I can get away with a removable fitting, DUMB or maybe I should say WET ASS.  At least it is summer and I wasn't taking that shower in freezing weather.)

You get the award for braving the embarrassment and yet telling everyone of the "silly" mistake you were making and hopefully thereby helping save some one else from making the same mistake.

[Vlad Jovanovic]

Thanks for the tip on those couplers TC. I will be sure to use them on the irrigation system when the two Sweedish WWOOFER's are around 

[TCLynx]

oh you dirty dog, or maybe not so dirty after getting the shower with the wwoofers