I'm in a bit of a quandary. I have a 4 yr old low tech 20g tank. Despite being an experienced aquarist of decades it was my first successful planted tank.
It has inert 2mm gravel (with small amounts of aquasoil underneath, injected in boluses, instead of root tabs) and amazingly most plants have done really well for most of its life. It has also housed a variety of shrimp and small fish, who have also generally thrived. It has been a lovely planted mixed display tank.
Here's a pic of it in its past glory
Sadly over the last 6-12 months some of the plants (definatley not all) have got harder and harder to keep going nicely and many of the shrimp have also been getting cloudy and passing away. GH/KH have remained rock solid stable. In fact nothing measureable has really deviated.
A real measure for me has been some Myriophyllum mattogrossense, which has lived in this tank for its entire life, growing superbly like a weed providing a lovely background stem jungle. However, recently even it is struggling, with dull colour, weak, thin stems and slow growth. I also used to have lovely Crypt wendtii, but the last couple now are simply holding on for dear life it seems. Growth is VERY slow.
Here's are recent pics
Its not a disaster. The java fern and buces are doing well but the crypts and Myriophyllum are hanging on (the pics don't really show the colour differences compared to earlier generations). However, the clearest indication for the Myriophyllum for me are the delicate, thin stems, which are definately a new thing.
The only things that have actually changed over the last year or so have been firstly (and possibly obviously) that the tank has aged another year, and secondly that I have converted to a new fertilizing schedule. Literally nothing else has changed.
My thoughts are ..................
1/ Maybe the build up of mulm and detritus in the substrate has become so much that it is increasing toxic dissolved organic compound levels, increasing the growth of nasty suspended bacteria, with negetive results on delicate shrimp (these are mainly softwater Caridina that are suffering. The Neos seem to battle on regardless). Maybe this same detritus build up is also affecting root growth and function in the rooted plants. Note - it certainly seems that my rhizome plants are still growing really well. Does this substrate and tank just need a jolly good clean out ? if I take all the substrate out and rinse it with clean dechlorinated water I should hopefully not completely wipe out the substrate microflora.
THis pic doesn't show the build up in the deeper substrate well but it does show that the substrate surface is really nice and clean. No detritus at all.
2/ Maybe this tank just doesn't get on well with the new fert schedule. This would be very surprising to me, as I use exactly the same chemicals and ratios (scaled up) for my large CO2-injected tank (again similar inert substrate with aquasoil injection) and the plant growth for virtually all in that tank is outstanding.
In this low tech tank I use weekly doses of 1.1g KNO3, 1.1g K2SO4 and 0.22g KHPO4. My micros are provided by a weekly dose of 0.21g of Solufeed Sodium-free TEC, which claims this composition ....
I change around 30% of the water weekly. Water is RO, remineralized to 6 dGH, zero dKH . COnsumer nitrate test kit tested levels in the tank seem fairly stable around 10-15 ppm.
I see no obvious signs of copper toxicity in the shrimp (any variety of movement disorder or spasms).
It will be a royal PITA to wash out the substrate and I don't want to do it unless its necessary.
If anyone had some words of wisdom I would be very grateful. I would love this tank to start thriving again
It has inert 2mm gravel (with small amounts of aquasoil underneath, injected in boluses, instead of root tabs) and amazingly most plants have done really well for most of its life. It has also housed a variety of shrimp and small fish, who have also generally thrived. It has been a lovely planted mixed display tank.
Here's a pic of it in its past glory
Sadly over the last 6-12 months some of the plants (definatley not all) have got harder and harder to keep going nicely and many of the shrimp have also been getting cloudy and passing away. GH/KH have remained rock solid stable. In fact nothing measureable has really deviated.
A real measure for me has been some Myriophyllum mattogrossense, which has lived in this tank for its entire life, growing superbly like a weed providing a lovely background stem jungle. However, recently even it is struggling, with dull colour, weak, thin stems and slow growth. I also used to have lovely Crypt wendtii, but the last couple now are simply holding on for dear life it seems. Growth is VERY slow.
Here's are recent pics
Its not a disaster. The java fern and buces are doing well but the crypts and Myriophyllum are hanging on (the pics don't really show the colour differences compared to earlier generations). However, the clearest indication for the Myriophyllum for me are the delicate, thin stems, which are definately a new thing.
The only things that have actually changed over the last year or so have been firstly (and possibly obviously) that the tank has aged another year, and secondly that I have converted to a new fertilizing schedule. Literally nothing else has changed.
My thoughts are ..................
1/ Maybe the build up of mulm and detritus in the substrate has become so much that it is increasing toxic dissolved organic compound levels, increasing the growth of nasty suspended bacteria, with negetive results on delicate shrimp (these are mainly softwater Caridina that are suffering. The Neos seem to battle on regardless). Maybe this same detritus build up is also affecting root growth and function in the rooted plants. Note - it certainly seems that my rhizome plants are still growing really well. Does this substrate and tank just need a jolly good clean out ? if I take all the substrate out and rinse it with clean dechlorinated water I should hopefully not completely wipe out the substrate microflora.
THis pic doesn't show the build up in the deeper substrate well but it does show that the substrate surface is really nice and clean. No detritus at all.
2/ Maybe this tank just doesn't get on well with the new fert schedule. This would be very surprising to me, as I use exactly the same chemicals and ratios (scaled up) for my large CO2-injected tank (again similar inert substrate with aquasoil injection) and the plant growth for virtually all in that tank is outstanding.
In this low tech tank I use weekly doses of 1.1g KNO3, 1.1g K2SO4 and 0.22g KHPO4. My micros are provided by a weekly dose of 0.21g of Solufeed Sodium-free TEC, which claims this composition ....
| Element | Soluble in water (%) | Chelated by EDTA (% min) | |
| Boron | (as polyborate) | 0.92 | N/a |
| Copper | (as CuNH4EDTA) | 0.23 | 0.23 |
| Iron | (as FeKEDTA) | 8.4 | 8.4 |
| Manganese | (as Mn2KEDTA) | 2.00 | 2.00 |
| Molybdemum | (as molybdate) | 0.15 | N/a |
| Zinc | (as Zn2KEDTA) | 1.16 | 1.16 |
I change around 30% of the water weekly. Water is RO, remineralized to 6 dGH, zero dKH . COnsumer nitrate test kit tested levels in the tank seem fairly stable around 10-15 ppm.
I see no obvious signs of copper toxicity in the shrimp (any variety of movement disorder or spasms).
It will be a royal PITA to wash out the substrate and I don't want to do it unless its necessary.
If anyone had some words of wisdom I would be very grateful. I would love this tank to start thriving again
