Backyard Aquaponics
A place to discuss aquaponics

VB....awesome looking bed of greens. Where's your stock tank? Do you have a pond?

Steve - I cracked when it came to the troughs, and somewhat regretaby I might add. Mine don't supprt gravel very well due to sagging between frame spars. The plastic tub is thin and needs more support to drain properly. I will spend more money reinforcing the tub after spending a couple hndred on initial purchase.

MF - 2 free standing poly ponds joined together with a 3 inch (??) tube. Fish are currently only in one of these, but I need them hooked up together so they do not run too low on the flood cycle. Altogether they probably only hold 700 or so litres.

This is my test setup. Plan is to get a 5000 litre tank when I have shown the wife that it all works.

Did my iron and KH/GH tests for the first time tonight. Did not register any chelated iron in the system. This does not suprise me as my plants are looking a bit yellow on the edges. Do I get chelated iron supplement from a hydro shop? Is this the only place I can get it? How much would I expect to pay?

Re: the KH - it took 4 drops to change the colour, hence suggests about 71.6ppm kh (which is okay I think). GH did not work because of me having 5ppt salt in the pond. I put in 20 drops and the colour still hadn't changed (suggesting extremely hard water). I gave up at that point assuming the salt was the issue.

the chelated iron you can also get from plain old gardening nurseries and such. But I am told that wihin a very short amount of time after adding the iron the levels again go to zero as the plants take up all available iron in the water. THis came from a good source. so i usually go by the color of my leaves. I was also having iron issues with my plants.

Hi VB:
The chelated iron I got from the store has other minerals in it like manganese and boron. It also has copper. I am wondering about that because I added a little bit last night and this morning I have four dead goldfish. Might be other things like the temperature has been a bit chilly the past few days, I'm not sure about anything yet. I have been adding about two tablespoons like once a week. I think the plants need something because they are starting to show signs of lack of minerals. I am looking into copper toxicity now...

DD, that sounds like a lot of chelated iron. I only add 1-2 tablespoons once a month or so in my large flood and drain.

VB, sodium chloride shouldn't interfeere with the GH test, it measures calcium and magnesium ions. I've made the mistake of looking for the wrong colour change, adding god knows how many drops when the colour change happened with the first drop (just wasn't a change, casue it was the first drop ) Damn, i cant find my kh / gh instruction booklet.

I followed the instruction exactly. Water is meant to turn from orange to green to show the GH reading. My water just kept getting more orange. I stopped at 20 drops (without change of colour) when the chart only goes to 12. I will do test again tomorrow. Is it possible my water is that hard. If so, I wonder what the implications are.

VB, do you have a scanner? can you scan me the instructions, as i have lost mine some how

I seriously doubt your water is that hard. you're looking at 350+ PPM GH

The colour change for gh is oposite to KH if memory serves..........

VB, been thinking about it, and it just don't add up!!!!!!!!


Did you use a clean test tube?
Have you done the test more than once?
Have you added any aquarium salts or emsom salts recently?

If you're worried about running outta your test kit you could always try diluting the test sample 1:3 with distilled water, then test. your ppm will read 1/4 of what it really is.

You gonna have me thinking about tis all night now, so please post back

VB, seems like you tested correctly.

I found some instructions on the net.
is this the same as yours?



OK, if your salt was normal table salt then it should be close to 100% sodium chloride, and not effect the GH. (comes from salt mines and is then further refined)

Great link here http://www.saltworks.us/salt_info/si_go ... erence.asp

If however it was sea salt, then it comes from the ocean and may have varying degrees of refinement.

how many PPT salt do you estimate you have in your tanks now?

Can you do a GH test for me on the water you use for your pond, (tap or tank)

Steve - that is pretty much what my instructions say. I put a kg of sea salt in the pond a couple of days back. I expect this may be the reason for the reading. The pond is probably at about 5ppt salt - the rest was table salt (or cooking salt). Will do another test tomorrow see what it says and will also test the tap water. Thanks.

The sea salt will do it

Going by the table on this link http://saltaquarium.about.com/gi/dynami ... awater.htm

sea water should have a GH of about 1700PPM

Sea water is 35PPT salinitu

5 PPT is 13% that of sea water

So your GH will probably be at 221 PPM

plus the calcium from the KH (71 PPM) gives you about 292PPM

I reckon you were only a few drops away from getting a result

Pretty high but the silver perch should be fine in it .

I feel better now that i hvae figures to work out LOL

I have noticed that the fish have not been feeding well over the last 2 days. Ran some tests today and found:

Ammonia - .5
Nitrite: - 1
Nitrate - didn't test it cause I figured that was the least of my worries.
PH - 8

This is weird as previous tests showed that my bacteria were boing a good job, leaving only nitrate in the system. The cahnges I made to the system (addition of big bed) should have had no effect on the bacteria as I have left my little bed in tact. I can only assume that the PH has had some effect on the bacteria.

In response to thes readings, I have done a large water change (about 40%). This will bring the ph down some and will also reduce the amonia and nitrate. I will test again tomorrow.

VB, Always refer back to the table on this page http://backyardaquaponics.com/forum/viewtopic.php?t=133

Although ammonia of 0.5PPM @ PH 7.0 is nothing to worry about, at PH8.0 it is the upper limit for fish health.

Nitrite of 1 i wouldn't stress about too much as you have a fair concentration of Cl- ions from your 5PPT salt.

PH in itself is still fine for the perch, but only with 0 PPM ammonia.

The ph of 8.0 is ideal for ammonia bac. so ammonia should really be zero unless you have added fish, gone on a feeding frenzy, or have really low DO.



Nitrobacter is the nitrite bac.

Some nitrite would be expected at ph 8.0 as its above the optimal range for the nitrite bac.

The water change was the best course of action for you. AA is right when he warns against knee jerk buffer additions. As you stated, you water change will have reduced you PH, while dropping your ammonia to almost 0.25 and your nitrites to 0.5.

Keep us posted