Backyard Aquaponics
A place to discuss aquaponics

Hello Peoples!

I'm new to the whole aquaponics scene and have been using these forums to help me set up my system over the last 3-4 months. I figured I should finally join the forum and say hi (and try find a solution to my problem)

I've used a couple of different peoples ideas and turned it into something a little Frankenstein - Something that I plan on expanding if all goes well! There is currently two fish tanks - ones a full IBC (1000L) and the other is 3/4 of an IBC with the top being used for the grow bed (approx 250 Litres worth of GB). As I tinker with it while I'm on break from a FIFO job, I have put some cladding around the water tanks using old pallets (trying to minimise the costs of the set up, so far I think its cost me less than $500 including fish and plants with the grow media costing nearly half of that!) I plan on adding more grow beds in the future if all goes well (hence the large volume of tank - plus I wanted to have incompatible species simultaneously)



Currently there is 10 silver perch in one tank, 5 barramundi in the other and 2 marron (down from 6). Cant see it in the pic, but the barra have a metal 'basket' they are in (about 80% of the tank) as I have more or less given up on the marron but wanted to give the surviving marron half a chance of not becoming fish food!

The fish seem to be growing fairly happily - but my plants don't - I have replaced the first lot of tomatoes, the squash have died and been removed... and the others are not looking too flash!! (see pictures - the tomatoes are new additions to try have another crack!)






The pump is a 3000 lp/h with it being split between the constantly flooded grow bed and the second tank with two air stones helping aerate the water (with a battery backup to try save the fish if power goes out!) - It has cycled as far as I can tell (jumped the gun and nearly lost everything when the nitrites spiked... long story but when I returned from work, the levels were reading 0.25ppm amm, and 0.25ppm nitrite with traces of nitrates and figured it'd completed while I was away as it had been nearly 2 months since i set it up)... And decided to throw the 5 barra in and another 5 silver perch (originally just had the 5 SP and 6 Marron)... managed to keep them all alive doing water change outs and salting the water! yay!

It now reads between 0-0.25ppm ammonia, 0 ppm nitrites and somewhere between 0-5ppm nitrates. The fish are growing and seem relatively happy. Feed pretty aggressively, especially the barra! The remaining marron are probably at least double their original size (one got attacked by the others, 2 escaped and found them in the garden on the other side of the property! and 1 MIA - assumed to be another escapee) however, they now have a cover on them so hopefully no more escapees! One of the remaining ones also has an unhealthy habit of climbing into the fish basket and anticipate it will become dinner once the barra get a little bigger!

Now for the fun part - As the plants have not been growing (dying actually) - I've been reading lots of articles trying to work out what the problem is.... and I think I have got it sorted (maybe) which is where I need your help!! Originally I thought it was some sort of nutrient deficiency, Plan A was to add seasol... seemed to pick them up a bit for a few days, but then continued to decline. On to Plan B - seem to show iron deficiency problems (so i thought) - so I added about 2 scoops of chelated iron as I read somewhere on here somewhere when I was trying to work it out... few weeks later, it seems to have made little difference!

As I read more and more information, I think I've finally found the problem - and something I haven't mentioned so far - is the pH levels! They currently sit very high (8.4).. Tap water in the area is around 7.8 which I put through an activated carbon filter to remove the chlorine (or at least reduce). The grow media is a combination of expanded clay and zeolite (was recommended to put some in). I was also told to add some powdered limestone by the place I bought the fish from when starting the AP system which I did (and suspect is the cause of my problems!). I have started to try lower the levels by adding HCl to it (in small amounts which does reduce the levels, but within a few hours it gets buffered back up to 8.4ish). I've tried to remove some of the remaining limestone dust to no avail (just end up stiring it up and making the water all cloudy again!)... Would this be the problem? And secondly, is there anything I can do or do I just have to wait till all of the basic material is neutralised? I also pulled some of the zeolite out of the grow bed and chucked it in the HCl, with it giving off gas - so assume this would also be contributing to the higher pH levels?

As the zeolite is mixed in / combined with the expanded clay, and the powdered limestone is in the fish tank, it's probably near impossible to remove it without starting again and probably buying new media (wish I had known this before starting... now that I'm having problems I've done a lot more reading than I did prior to starting and just went with advice from a place that had several setups at their shop and trusted their advice!!).. Is there anything I can add to naturally release / slowly reduce the pH without causing the levels to bounce all over the place (as the fish don't seem to like it when the acid is added! - usually only drop the pH by about 0.5 at a time before its buffered back up) In the mean time, are there any plants / vegies that like high pH soil I can plant that will keep the system balanced until all of the material is neutralized?

Thanks in advance!
Russell

Hi Russell, welcome to the forum

Looking at your plant problems and it looks like a deficiency to me. Perhaps more than one. The first thing I noticed was that the lower leaves were yellowing and curling up on some of the plants. When you see something like this it's usually due to a mobile nutrient - the nutrient is being moved out of those lower leaves and into the upper/new ones. My guess is that this is indicating a potassium deficiency which is pretty common in AP systems. Often the edge of the lower leaves will be the first part to turn yellow and will sometimes die. A good example is the parsley plant. Parsley really likes to have potassium so sometimes it's the first to indicate the problem.

I also noticed that there are some plants that have a general yellowing all over the plant. This could either be nitrogen or a combination of potassium and iron. Tough to say.

Basically you'll have to wait for the buffer to get used up before the pH will come down and stay down. Eventually it will but it will take a long time. Adding acid will hasten the process but will still take a long time. Expect maybe a year or two of this unless you're feeding a lot or adding acid. You don't really want to change the system pH by any more than 0.4 pH points at any given time because it stresses the fish. Most fish can handle more than this so it isn't the end of the world if you accidentally overshoot but it's better if you don't.

Iron is a non-mobile nutrient so it would show in the new growth first because it can't be moved from the old growth like potassium. Depending on how the plant grows thats often the top of the plant that turns yellow. The high pH is a pain but you can spray apply iron to avoid pH lockout or you can use Fe-EDDHA iron chelate in the system water and it will still be available where other forms of iron won't at this pH.

I'd also spray apply the Seasol. FYI, depending on which version of Seasol you're using, it's mostly about growth promoters not the nutrients themselves and without the nutrients you still won't get the growth you want.

I noticed some of your plants are bolting. Temperature sometimes causes this and that could also be the cause of some of the curling on the lower leaves. If it's getting really hot during the day you may want to provide some shade for the grow bed.

With a pH of 8.4 you have very little leeway before ammonia becomes toxic. I don't know what water temp you have there but 0.25 may actually fall into the toxic range at that pH if the temp is also high. If your system falls into the toxic ammonia levels based in this chart then don't feed until the ammonia falls to zero - http://ibcofaquaponics.com/information/tables-and-charts/

That's all I can think of for now but that should keep you occupied for awhile

Hello Scotty

Thanks for the reply - a bit more food for thought!

I have the 'plain' version of seasol - http://www.seasol.com.au/products/61/Seasol and have used a watering can to put it over the plants and grow bed - which did seem to give it a couple of days relief but not much! How much should I be adding? there'd be approximately 1800 Litres of water all up in the system. I'm guessing if its a nutrient deficiency my best bet would be to add more? How much of the iron chelate should I add? The one I have is 13% (http://www.manutec.com.au/default.asp?p ... id=MTO0522) and added two scoops (guessing 10 grams or so?)


The plants have practically not grown since i put them in except the cos lettuce (went to seed) and the original tomatoes grew really weedy (and practically died) - they've all been in there for probably 3-4 months now and that's what they look like!

We did have a few hot days (40 degrees plus) so that probably didn't help the cause! they do get shade for part of the day (afternoon from the shade cloth casting shadows on them) and the water temperature moves a fair bit (between 22-28 degrees Celsius) based on the weather. Its been fairly erratic with hot days here and there, with not much consistency!

To be honest, the ammonia is below 0.25, but sometimes I get a little bit of colouration so its obviously not 0.00! The kit I have cannot distinguish between 0 and 0.25 ppm, as such so I said 0.25 on the 'side of caution'. Checked the charts and as little as 0.12 is toxic

The fish don't seem bothered by the high pH only when I mess with it by adding acid... even 0.5pts is enough for them to stress out.. only messing with it in the hopes the plants might start growing!!

Edit: And they are being fed around 7-8 grams a day at the moment of a aquaponics blend if that makes any difference

Hi Rusty, welcome to the forum!

Yup, your pH and the hot weather are combining to cause your problems, I think. You've got nutrient lockout making all your 'hungry' plants (tomatoes, capsicums etc) unhappy, and the leafy greens that would probably do OK otherwise are bolting because it's summer. You can temporarily make your plants a bit happier by spraying the dilute Seasol directly on them the way you have been (don't bother putting it on the growbed for now, at best it'll do nothing and at worst it'll build up). I can't tell what form of iron chelate that is, and most types aren't accessible by the plants outside of a fairly narrow range of pH, so best to mix it in with the Seasol when you're spraying it. Note, don't spray it on when it's sunny or hot - wait until early evening so your plants don't get burned.

First thing to check: what is the pH of your tap water after it's sat in an open container for at least 24 hours, and is your water hard? A lot of the time if you test the pH right out of the tap it will actually show up as lower than the 'true' pH due to dissolved gases, and hard water contains more of the 'buffers' that will make it more difficult to bring your system pH down. (Yup, the powdered limestone will definitely be acting as a buffer too.)

Next, you can probably get some of the limestone out by 'vacuuming' it out with a siphon. If you can't, eh, don't stress about it too much; you'll still be able to bring your pH down, it'll just take longer.

Nitrification will eventually bring your system pH down, if you can top up with lower pH water that isn't full of buffers. Can you collect safe rainwater to top up with? If not, you're going to need to treat your topup water before adding it. Run it into a good big container (oh look, an excuse to get another IBC or a food transport barrel...) and dose it with hydrochloric acid (available from some hardware stores). Do this carefully and handle the acid with extreme caution - if there are different concentrations of acid available, get the lower concentration as it is safer. (Also, always put the water in your chosen container and then add the acid to the water, not the other way around!) Get it down to a pH of about 6.5, then leave it overnight and test again to see if it's bounced back up; if it has, dose it down again and re-test. Keep a record of how much acid you need to bring that much water down in pH so later on you can do it in one go (but do always test to confirm the final pH as your tap water may vary), then use that water to top up your system.

Eventually your pH will come down as the buffers in your system are exhausted, and you may end up needing to work to keep your pH up, in which case being able to top up with tap water that you've just let sit long enough for the chlorine to gas off will be very convenient.

Spray apply the Seasol - according to the package instructions should work OK - http://www.seasol.com.au/products/61/Seasol. Same with the iron chelate - I'm not sure but it looks like this is iron edta which is not going to work well when added to the system water at the pH you have. There should be instructions on the box for spray application, just follow those. You might be able to increase the frequency of spraying from what they suggest but I wouldn't change the amount sprayed that they suggest. If it looks like you're getting leaf burn, you've over applied.

Many fish can handle a high pH like this the problem is really getting the nutrients to the plants and mostly that's about Iron because of pH lockout.

I'd pull the plants that have bolted. Another thing to consider is that plants that have been stunted may never recover (some do, some don't). You might be better off on some of these with just getting some new starts, rinsing the soil off and popping them in the grow bed. Maybe just try it to replace the ones that have bolted but don't plant lettuce or cool weather plants if you've still got high temps or you'll get the same result.

You'll get a little bit of potassium from the Seasol (it's about 2% potassium) but there are better sources (use Seasol anyway just don't expect it to cure the potassium deficiency). Do a search and you'll probably find something to help with this or someone else will chime in to help with this. I think Yavimaya might have posted with some other ideas in the past.

If you've supplemented for a couple of weeks and the plants aren't getting darker or nothings growing still then try sprinkling blood and bone meal into the grow beds but go easy since this is a source of nitrogen and could cause an ammonia spike (haven't seen one yet but it's better to be cautious). I believe the normal dose for this is 50 gm per 100 L of media but since you have fish a pretty high potential for ammonia problems, try half that.



Yep, this is a problem. It's common to get a trace of ammonia and usually it's OK but in this case you want it just as low as it can be. If you don't feed for a day and the level is the same tomorrow then it may just be the kit. Try light feedings and see what happens. Doing things like spreading out the feedings to several small feedings vs one large feeding will help prevent a large ammonia spike. Make sure that you clean out any uneaten food and that there are no dead fish or animals in the system as well.

Don't add any more fish unless you add more grow beds or some other type of filtration.

Hello Mel Redcap

Am I better off just mixing the seasol in a little squirty bottle n giving the plants a spray every couple of days when I'm home rather than mixing up a watering can n just pouring it all in?

I read the packet on the iron chelate - its the edta version.. so Scotty it seems a little pointless mixing it in the water!! Haha gotta love learning the hard way I am learning what NOT to do very quickly as it seems... didn't quite read enough before I ventured out and started a AP system (thought I had and took some wrong advice along the way it seems!!)

The pH of the tap water is the 7.8-8.0 I said earlier after waiting 24 hours, straight out of the tap its a bit lower around 7.4ish.. I have slowly been adding HCl straight into the fish tanks to try hurry up the neutralisation of the limestone / zeolite, though, like I said before the fish don't like it (and I only drop it down to around 7.8-8 each time) and wait for it to come back up before doing it again... I'd assume this isn't the best for the fish or the plants? I have tried to suck some of the limestone powder out but not with much success to be honest.. from Scotty's advice, I'll start using less HCl and drop the pH less each time to limit how much it 'bounces. I will also try drop the pH of some tap water to see how much it buffers it - I havn't bought a hardness test kit yet, which I may need to invest in!

I wont be adding any more fish - I'm probably at the limit from what I understand without adding more grow beds and the fish eat the food in under 2 minutes (if that!) - the barra smash the food and after about 10 seconds they are done and don't touch whats left (which I then remove)... the Perch polish it off pretty quickly and could probably feed them more but slow n steady does it for now (I've got enough drama's as it is!) The only food that sits in there for any period of time is a few little pellets I sprinkle around for the marron to eat (usually gone the next morning but its only a few little grains at a time), and the dead are cleared asap (luckily I haven't actually lost any fish and only 1 marron that was killed by its mates! *touch wood*)

Thanks again for the tips / advice... Hopefully things will start to turn around soon!

Yup, a little squirty bottle with Seasol and iron is probably the way to go. Don't worry, nobody ever reads enough before starting - we just move on to more advanced mistakes earlier! Definitely try dosing some tap water down, if you've got a lot of buffers in your water (which I bet you do given the pH) then adding HCl into the system without dosing your topup water isn't going to do much except stress your fish.

Hi Russell,

ouch. steep learning curve that one.
Are you Perth metro ? Are you NOR or SOR ?
makes a big difference for your tap water and what options you have.

The plants will be suffering from the full sun this time of the year anyway, and for stressed plants it is just another thing to deal with and not so great if you are foliar spraying. I would put shadecloth over the top for next 6-8 weeks (through to March to cover Feb heat). Will help the fish as much as anything.

evaporation should help with you basically doing water changes. And I would water change 50-100L or so at a time anyway when you can (every couple days or so). Pre-treat your top up water with HCl as per above posts. Getting good amounts of silty water out and/or vaccumming as Mel suggests would help to get rid of some of the limestone powder.

Option may be to let the vegies go in that bed and plant something else just to focus on having something growing.
root pouches or someting earth based may actually help - basically like wicking pots with the bottom 1/3 in the grow bed. You will have better chance with the plants - and you mainly want them using nitrates.
You really just need to keep the fish going at the moment. That pH will be an issue for most things.

** your #1 issue for fixing things atm is the limited volume of cycled media, basically you cant do much with just the one bed because you will lose your nitrification.
As you mention needing more beds best option is to set up a new bed or 2 and hook these in.
Ideally to your better fish tank or even a new one. Let them run and settle (get bacteria in place).
With what you have you really need at least 2 grow beds and probably 4 (2 x 2) anyway.

Once you can remove the existing bed out give the media a really good rinse with some form of sieve and a bit of a light acidic (low pH) water bath. Then the media should be fine to use again.

personally I like Mels idea of adding another water volume that you can treat easier.
even if it becomes a temporary fish tank while you sort out one of the others etc.
If it is part of the system (via ball valves) then you can wash through without doing things in the actual FT's.

the zeolite is a bit out of left field ?? Where it has been used it is usually kept in bags. Very few in AP would use it (beyond BuiDoi).

Thanks Mel - I will try acquire another IBC or 44 gal to treat water before it goes in! (it does run through an activated carbon filter first, which I'm lead to believe will remove the chlorine and some other bits n bobs... but I've been led astray in quite a few things so far, so now I'm not sure how true this is! my limited research tells me it does help)

Hello DLF- I'm on the river? hahaha technically south (vic park/Carlisle). I was always planning to add another grow bed like the first onto it and maybe a couple of 44 gallon drums cut in half - but wanted to get it all up and running and see how it went before I made it too big... seems I may need to expand things just to keep it going!! I'll have to try get my hands on another IBC it seems!! I probably wont use expanded clay again due to the cost though or is it really worth paying the extra? - what else is a cheaper alternative that works well? I've seen pea gravel being used but obviously weight becomes a problem?

I suppose once I have a second grow bed sorted, I can just disconnect the first and bath it in concentrated acid to get rid of all the buffer material, rinse, and reconnect to the system... which should hopefully eliminate a lot of my problems... How long would it take for all the friendly bacteria to find a home in the new grow bed if it was just linked into the existing system? (i.e. how long before I can remove the original without screwing things up more!!)

The zeolite is supposed to help with storing nutrients and releasing them to the plants when needed, or at least that's how it was sold to me!

Cheers

>> Hello DLF- I'm on the river? hahaha technically south (vic park/Carlisle).
I'm close to Curtin Uni so not far away. You should/will be OK for tap water as it is mostly buffered desal down this way.
pH, GH and KH are a massive issue for those to the north who are fed groundwater.
The water pH will be high 7's over summer but will drop down OK in winter - mine is mostly 7.6-7.8 out of tap and systems sit at 6.8-7.6 quite easily. Dive to 6's when I have issues.

If Carlisle water quality is anything like mine you can literally spray it direct from the tap - so de-gassing is pretty easy and water changes will work for you. Good news is that the limestone wont be as big an issue if it stays in system - it will probably stabilise by mid-winter so you really just got to get to May or so.
In this area will probably have issues the opposite way in a year or so . You will be adding carbonates...

>> I'll have to try get my hands on another IBC it seems!!
that is really the ideal pathway... your fish will overload that one bed pretty quickly anyway.

>>I probably wont use expanded clay again due to the cost though or is it really worth paying the extra? - what else is a cheaper alternative that works well? I've seen pea gravel being used but obviously weight becomes a problem?

hard one. Lots of non-clay stuff gets pretty hot. I have pea gravel in other things here and brought it by half trailer full. It is good when it is submerged but you do need to wash out the finer material. A few people have done half-half with rock at bottom and clay media on top.

Look around for the clay, prices vary a bit..... discounts for buying a few bags etc.

pick your AP supplies shop The one attached to this web site (Jandakot) is pretty good and honest.
They don't get too carried away about telling you that you need to buy stuff....

>>I suppose once I have a second grow bed sorted, I can just disconnect the first and bath it in concentrated acid to get rid of all the buffer material, rinse, and reconnect to the system... which should hopefully eliminate a lot of my problems...

that would be the plan.

not conc acid... just wash it out and sieve with tap water. then give it a bath in low pH water (6.5 or whatever).
then rinse it again. [edit] HCl in rainwater would be ideal as there is no buffer.

>>How long would it take for all the friendly bacteria to find a home in the new grow bed if it was just linked into the existing system? (i.e. how long before I can remove the original without screwing things up more!!)
warm weather should be OK within a week (connected to a working system), 2 would be safe.

>>The zeolite is supposed to help with storing nutrients and releasing them to the plants when needed, or at least that's how it was
Yep its had a mention here but usually as a way of having low/no grow beds and I doubt many here would be jumping on the band wagon based on the thread. Definitely not a main stream recommendation for a basic starter AP system.

More dead plants

Still adding a little acid each day.... Eventually I will get rid of all the buffering material

Any plants that have a tolerance to higher pH? Its sitting around 8.2 now after it buffers itself back up... still too high


Next break off work I'll try acquire another IBC and add a new grow bed and remove the old one from the system, try remove all of the zeolite and start again! On the plus side, the ammonia levels are back to 0, and the fish are growing quite nicely!

Hello All

Little bit of an update - I have added a half barrel to the system, waited 2 weeks for the friendly bacteria to do their thing in there, and pulled out the original bed so at least some filtration was available. Cleaned out the zeolite (as best as I could) and put the original bed back into the system. I'd say at least 95-98% of the zeolite would be out... I think it would be near impossible to remove it all without some proper equipment!

The pH is still high sitting at 8.0, but added a little acid to drop it down again (hoping it will actually stay down this time or at least take a lot longer to rise!)

The plants in the half barrel seem happier than what the others had been in the original bed even with the higher pH - so i'm guessing the roots in contact with the zeolite was making them suffer even more! The other levels seem to be fine after cleaning out the bed (so far no ammonia, nitrite or nitrate spikes). Hopefully I will start to see some progress!

Luckily, the fish don't seem to be bothered at all about the whole thing... they're happily growing as far as I can tell - the barra would be approaching 25-30cm, silvers between 5-15cm (some were added later), and the marron's body length is around 10cm.

Note to self... and anyone else... don't put zeolite in the growbed (even if advised to do so!)

Fingers crossed!

Yay!! Finally after nearly 6 months, Pulling out the grow bed and trying to sift out the zeolite I was told to add, and adding acid most days to try neutralize what zeolite I couldn't get out and bring the pH down from the 8.4, the pH is now sitting around 7.2 with only adding a few ml of acid every couple of days which I will stop doing and see if it keeps climbing!

Been a pretty harsh learning curve! Few sets of plants later, they finally look like they are starting to grow!

Cheers everyone for their inputs!

Good to hear Rusty.

also the weather has now turned to optimal for plants - so probably the Jan/Feb issues had as much to do with heat and full sun. Next year get some light shadecloth - 30-50% or so from eBay. That will help as well.

Get the additional grow beds in, you need to be using up what the fish are producing and the types of fish you are raising are not as forgiving as Goldfish.

>>The plants in the half barrel seem happier
Other option is to go with some 20L drums filled with media and run them as large dutch buckets.
Bit like Brian is doing....viewtopic.php?f=45&t=28359
That way gets some new media into system and these are great for larger plants (and have a screw fitting for outlet already)

be very careful about lowering your pH too much. Winter usually sees a drop in pH so going in at 7.4-7.6 would not be a bad thing. I run with same water as you and in winter struggle to keep my pH at 7+.

For what its worth IMO that type of grow bed is no good for growing tomatoes.
OK for the leafy greens etc. Cos Lettuce, kales etc
I never had much success with tomatoes until I went to dutch buckets - 1 bucket for each plant.
Bit of extra Blood&Bone with potash and the odd dose of magnesium and other trace elements.