Water quality for blackwater tank for adoketa.

[martink]

Hi so im going to start a nice blackwater tank to house some Adoketa. I've been out of the hobby for a long time and I thought I'd ask help on water quality. I included the hardness review of my tap water by council and measured a ph one day of 6.9 then the next of 7.8 which was confusing. I have a lot of wood and dried vine for a root complex, I have bought sand that does not affect ph and will have a substrate of organic peat capped by sand. I will attach peace lilly and monstera to the tank to root into the water column and eventually the substrate. the tank is 100x40x40 mm. Any advice on set up would be much appreciated. I am often very, 'throw it up see if it works', but this time I'd like to get it right. thanks.

 

[MacZ]

I have a lot of wood and dried vine for a root complex, I have bought sand that does not affect ph and will have a substrate of organic peat capped by sand. I will attach peace lilly and monstera to the tank to root into the water column and eventually the substrate. the tank is 100x40x40 mm. Any advice on set up would be much appreciated. I am often very, 'throw it up see if it works', but this time I'd like to get it right. thanks.

I would not use the peat capped under the sand, either mix it (3 parts sand, 1 part peat) or use the peat in a filter media bag. Otherwise this sounds all good.

I included the hardness review of my tap water by council and measured a ph one day of 6.9 then the next of 7.8 which was confusing.

With such low hardness readings it might be possible your KH is even lower than GH. You are already in the range where pH-tests do not work properly anymore, as they are linked to KH. Below a KH of 2° the tests give erratic results.
I'd invest into a TDS/EC meter asap.

Your readings are otherwise in the range where you can get KH down to 0 or rather below detection, which is key for blackwater. With enough humic substances thanks to the peat a pH-crash is impossible, as they buffer in the low range between 4 and 6, so you will only have to check TDS and EC. For those readings of 10-50mg/l TDS = ca. 20-100µSi/cm in EC are what you will be aiming for. Note that real blackwater is below an EC of 20µSi! Readings like this will only be achievable with RO or DI water.

I would estimate your readings if you stick to the water source unaltered only using peat to end up somewhere in this range:
TDS 60-70 mg/l
EC 120-150 µSI/cm
pH (if you find a reliable way of measuring) 5.5 - 6
GH 1-2°
KH below detection

 

[MacZ]

Oh, and a little addition:
Water quality comprises of nitrogen compounds, other organic waste products, DOC, as well as heavy metals and other toxic materials. This should always be a given to be perfect.
What you are asking about are water parameters: hardness, acidity/alkalinity, TDS, EC, salinity, temperature. Basically non-organic and/or non-toxic dissolved substances and physical properties. This can vary widely depending on what fish you want to keep.

 

[martink]

Oh, and a little addition:
Water quality comprises of nitrogen compounds, other organic waste products, DOC, as well as heavy metals and other toxic materials. This should always be a given to be perfect.
What you are asking about are water parameters: hardness, acidity/alkalinity, TDS, EC, salinity, temperature. Basically non-organic and/or non-toxic dissolved substances and physical properties. This can vary widely depending on what fish you want to keep.

thanks for all the info. Ill mix the peat with sand. and get the tds/ec meter. maybe i could buy this if the tds is too high... https://www.amazon.co.uk/Finerfilte...df-8718-2b3116cebc1b&pd_rd_i=B01NBHNKDT&psc=1

i know its the cheap one.

 

[MacZ]

maybe i could buy this if the tds is too high... https://www.amazon.co.uk/Finerfilte...df-8718-2b3116cebc1b&pd_rd_i=B01NBHNKDT&psc=1

i know its the cheap one.

It's completely sufficient. I'd take the model without the DI-Stage. With your water parameters from the tap the RO membrane should work quite efficiently because there isn't even that much to filter out. And probably it will run longer on the first membrane than with harder water.

 

[martink]

It's completely sufficient. I'd take the model without the DI-Stage. With your water parameters from the tap the RO membrane should work quite efficiently because there isn't even that much to filter out. And probably it will run longer on the first membrane than with harder water.

so handy thanks very much.