Lowering pH and TDS

[Bramgroet]

Hello everyone,

I have a 100x50x40 cm aquarium. Effecttively around 180L. It is Rio Negro inspired but I can't get the water parameters right.
The water parameters now are:
TDS 120 ppm
pH 6,5
KH 2

The fish in there right now are:
male A.piaroa
12 nannostomus marginatus
1 farlowella sp. (not from rio negro)

I have a female A.Piaroa in a breeding tank with fry. Now I want to lower pH aswell as TDS. I can use RO water.
Now my problem is that I cannot make enough RO water and I don't have the storage for a weekly 50% water change. I could do like a 50L waterchange weekly with RO water. But is this a not big enough water change?

The water parameters of the breeding tank are much lower since it is less water I can do big RO waterchanges easier.

Another question off topic. The male apisto is pretty dark his fins are coloured up he gets fed frozen foods like black mosquito larvae, artemia and I sometimes give fresh bbs. Could it be water parameters, the fact that he isn't with the female so he doesn't have to colour up or lack of cover, which I don't think it is?

Thanks in advance.

Ps please don't mind the rather bad English I am not English or American.

 

[MacZ]

I have a female A.Piaroa in a breeding tank with fry. Now I want to lower pH aswell as TDS. I can use RO water.
Now my problem is that I cannot make enough RO water and I don't have the storage for a weekly 50% water change. I could do like a 50L waterchange weekly with RO water. But is this a not big enough water change?

The stocking density is very low, so you could get away with 50 liter waterchanges of pure RO (with humic substances) a week. You should first do a row of several 50l changes in one week to give it an initial push. That allone should do something. Just keep it to RO after that.
How stable are the other parameters? Nitrogen compounds etc?

Another question off topic. The male apisto is pretty dark his fins are coloured up he gets fed frozen foods like black mosquito larvae, artemia and I sometimes give fresh bbs. Could it be water parameters, the fact that he isn't with the female so he doesn't have to colour up or lack of cover, which I don't think it is?

No female no need to flare. But if a fish is generally rather dark, it's the environment. If I remember your tank correctly it has a dark background and not the brightest of lighting. Get a small mirror and hold it against the glass. See what happens. Usually the fish flare up then. Remember, Apistogramma have several colour schemes depending on mood and situation.

 

[Bramgroet]

The stocking density is very low, so you could get away with 50 liter waterchanges of pure RO (with humic substances) a week.

I already add humid substances. I am planning to add the female back and add a dozen of cardinals.

How stable are the other parameters? Nitrogen compounds etc?

The NO3 test is expired. So I need to buy a new one. But phosphate and Nitrate where rather stable.

 

[MacZ]

I already add humid substances. I am planning to add the female back and add a dozen of cardinals.

take it slow. Re-introduce the female, change the sourcewater and wait at least a month. If the TDS/EC stay low between further changes you can stick to smaller changes and slowly stock up with cardinals. But do 2 6-piece batches and quarantine them well. Lately a lot of cardinals come in with Dermocystidium into Europe. Not that this is dangerous, but it's untreatable and annoying.

The NO3 test is expired. So I need to buy a new one. But phosphate and Nitrate where rather stable.

Phosphate is irrelevant for fish, NO3 is Nitrate. NO2 is what you should keep an eye on before stocking up.

 

[Bramgroet]

NO2 is what you should keep an eye on before stocking up.

NO2 is zero always otherwise I wouldn’t add fish. NO3 is probably pretty low but I will make sure soon.

Re-introduce the female, change the sourcewater and wait at least a month.

I was planning on doing since I want to rearrange the decor before adding the new cardinals. Cause I have a lot of oak which I have dried for 1 month and I will soak in cold water till it is almost sinking then I will dip it in boiling water.

But you would think that I could get away with a 50L weekly waterchange the named fish and the cardinals if I keep an eye on NO3 and NO2.

 

[MacZ]

Thing is, the beneficial microorganisms in the tank have to adapt to two things: Lower EC and higher bioload. Hence first change the parameters, then check if the readings stay stable, then add bioload in small steps. And find a way to store 100 liters of RO at any time. Or at least 75. Here also small steps do it.

 

[Bramgroet]

Alright thanks for the help. Also how do you get your RO water on temp?

 

[MacZ]

To be fair: I don't do waterchanges as such anymore, but have to refill 2.5 liters at room temp daily, because the about 10-15m of Pothos plant (5 separate plants, 2.5-3 m each) growing from the tank to my window suck a lot of water. And nutrients. I maintain about 30mg/l TDS / 60 µS/cm in the water that way. Plants grow excellent, the Nymphea just had 3 new offshoots. So basically between the oversized canister filter (rated for 300 liters on a 100liter tank) and the fact I use pure RO in a very low stocking density (2 Dicrossus, 5 Hemigrammus filamentosus, 6 Nannostomus eques) tank, I don't have to do waterchanges anymore. But this is a system that took a lot of time get truely going. I only stopped doing waterchanges after 16 months runtime for the tank. It will reach 2 years next month.

But: As long as I did regular waterchanges I used a designated electric kettle to bring a 1.5 liters of RO to boil then added them to 8-9 liters non-warmed RO in a bucket. Result: Exactly 25°C in the bucket. I often also used this to add the humic substances, by adding the hot brew to the bucket.

 

[Bramgroet]

But: As long as I did regular waterchanges I used a designated electric kettle to bring a 1.5 liters of RO to boil then added them to 8-9 liters non-warmed RO in a bucket. Result: Exactly 25°C in the bucket. I often also used this to add the humic substances, by adding the hot brew to the bucket.

That’s precisely what I do.

 

[Bramgroet]

Plants grow excellent, the Nymphea

Do you use root tabs or clay?

 

[MacZ]

Do you use root tabs or clay?

Nope. Just fine sand and mulm from the leaf litter on top.
These pics are from November.

 

[Bramgroet]

looks Nice. What kind of plants do you have right now?

 

[MacZ]

Several Nymphea lotus, Hydrocotyle leucocephala, Salvinia auriculata and Limnobium laevigatum.