Backyard Aquaponics
A place to discuss aquaponics

Almost finished my first aquaponics system, just need to finish some wood sheeting, and tinker a bit with the pvc pipes to get everything right. It is in a greenhouse, IBC tank 800 liter, 220 liter sump. 400 liter growbed, a small growbed and a small raft bed.
It has been cycling for about ten days now and I have been filling up the grow beds with small plants.
So far I have planted: tomato, beans, lettuce, broccoli, melon, strawberry, pepino, paprika, pepper, lemon grass, and various herbs. most plants are still small, but are starting to grow now.
After much doubting I decided to take non edible fish, they all dont get bigger than 3 inches so the IBC is big enough for them. I have rainbow shiners, White Cloud Mountain Minnow and "mona lisa" (I think you call them mona lisa) they are busy little fish and they seem very happyin the tank.
I dont know if I should put in more fish in the future when the plants get bigger, right now I have;
-5 mona lisa, 8 cm
-10 mona lisa, 5 cm
-32 rainbow shiners 4/5 cm
-17 White Cloud Mountain Minnow 3/4 cm

Water temp is 18 to 19 celcius, ph is 7.5 (My tap water is also 7.5)
Should I just give it some time for the ph to drop?
I am ordering a test kit this week to measure nitrate and nitrite etc.

photo's next post, when I deciphered how to post em...

Now you have to learn the most critical element of aquaponics, patience....... I've suggested to a few people in the past that the best thing you can do when you first start aquaponics is start another hobby at the same time to keep you occupied.

Essential image posting info near the top here viewforum.php?f=4

I asume you are implying that I should just wait for the system to "mature"

>> I asume you are implying that I should just wait for the system to "mature"

" It has been cycling for about ten days now"

no he is saying that you have another couple of weeks to go before cycling will be complete and sounds like you are trying to do too much too quickly. ie. don't try and do too much too quickly - it is a recipe for problems.

if you don't get a parallel hobby then simply sit back and rink a few beers/beverage of choice.
there is a lot of waiting for things to get to their respective balance.

My apologies for being stupid. As a beginner i simply do not know if the PH will drop naturally or if I can wait forever for that!
It's new for me and I have to learn about it, that's why I am on the forum! And what is this assumption that I need some other hobby because of impatience? I simply wanted to ask if I should do something about the ph or not.

Thanx for the heartwarming replies

The waiting is the hardest part, T. Petty.

My system from the start had a high PH, and even now after 2 years still is high. At first I was tempted to start tinkering with additives but I waited it out and there has been no harm. Fish and plants are doing well.

Unfortunately nothing happens fast (except maybe a raccoon decimating your fish) so just wait and see.

Cycling and developing into a mature system will take time.

It's not that I am tempted to do something, It's that I just didn't know if I should do something about it.
I read in another post that it is dangerous for the fish when the PH went close to 8 and I just wanted to be sure not to cause a mass die of right from the start. I also read that for the plants the PH is best around 6.8.
Being new to aquaponics I just do not know what causes the ph to drop in a system. And if I should "assist"with this.
I tried to find answers on the forum but its difficult to find an exact answer or topic sometimes.
But I get it now, No assistance needed, it will change in time. (if all goes well)

If your system evaporates water, do you just put in tap water and wait for it to "adjust"?
(I already put extra media on top of the grow bed, that has helped.)

I bought a test kit today and will test the water tomorrow.

I just tested the water. These are my results:
pH 7.5
kH 5
NO2 0.2
NO3 6
Fe 0
water temperature is 19 degrees celcius.

your numbers look OK.

>> re: ammonia testing (from other thread)

Yes you should test for that, it is the one most likely to kill your fish in the early stages if you don't have enough conversion capacity or if you overstock with fish. It is also important if you add supplements etc.

Don't worry about testing regularly for GH & KH. These are good to know - particularly for source water and system over time - but are not day-to-day things you need to test.


>> If your system evaporates water, do you just put in tap water and wait for it to "adjust"?

evaporation is an issue in warm/hot weather. It is increased issue for small systems and systems with shallow grow beds - hence why >10" is recommended for grow beds. (12" or 300mm plus is ideal with water at least 2-3"/5-8cm below the top).

How you deal with it depends upon you top up water and the volume required. If your water is just chlorine and pH is 7-7.9 then you can store it for 24 hours and then add it to your system. Best to do it in such a way that does not shock the fish.
If you find you need a lot of water then (a) your beds are probably too wet and your fish tank too exposed (b) you will need to get a 200L blue drum or something. Top that up, let it sit and then add it to your tank.

If you want to drop your pH (pH>7.9) then you can add HCL (hydrochloric acid) while the water is resting.

* If you have chloramines etc then ideally these need to be treated for before adding. In this case maybe you need a small rain water tank to store water and mix in/collect some rainwater when it rains.

* Sometimes if your water is very good, close in pH and you have hardy fish then you can add directly to the tank.
(not really recommended but a few of us lucky ones with good water can do it)

* if you have rain water that is a bonus *but* it has no buffering and will make your system acidic (low pH).
with rainwater fed systems you will need to add potassium bicarbonate/carbonate (for K) or hydrated lime or something similar for Ca. These can be added into the system and do not require pre-treatment.


>> re: high pH being bad.

High pH + ammonia + warm water = very bad for fish. But many people run pH 8 systems no problem - many don't have a choice because their water supply constrains them. It just means that you must not have too many fish and you need to make sure your systems is well cycled.

In AP pH 6.8 means you are likley to be always treating you system with potassium bicarbonate/carbonate or hydrated lime. The ideal place to be is anywhere pH 7 to 7.8 - but it is more important that your pH is stable and not constantly changing.


>> what is next

you probably need to locate some *low* nitrogen/phosphorous (N & P) liquid seaweed extract.
Your plants will need small doses of this to get additional things they need to grow.

not sure on your brands - what you want is something equivalent to Seasol (that you will see mentioned here)

Thanx a lot for the reply!

I wil buy an ammonia test today so I can check the levels.

I will lower the water level in the growbeds, now it's about 3-4 cm below the top clay pellets, Will make it about 7-8 cm. I think I am lucky with the tap water, we drink it! (we never buy bottled water here.)
The site from the watercompany gives the following values:
https://www.brabantwater.nl/PompStationInfo/Eindhoven.pdf
dH 5,99 - 6,27
pH 7,79 - 8,12
When I measure The tapwaters pH it's 7.5, I have been adding it to the sump,so it goes through the growbeds first before meeting the fish.

I have been searching for seasol, (it's not available here), I noticed its made from kelp.
I can only find a "garden mix" made from Ascophyllum nodosum. which is a different seaweed.
I will have to do a bit more searching for the right product.

thanx again for the help!

the seaweed extract is quite common, but in many countries it has added urea (N) and P by default.
The mix for the "white" bottle seasol mentioned frequently around is below...

when the system needs a bit of N & P we switch to the Seasol PowerFeed which has added N & P.
(around 4% I think).

I think those from England/UK have a product that is similar.