Pinatifida Problems

[Paul M]

Hi folks. I've noticed that my H.Pinatifida is not looking its best and seems to have yellowing leaves with dark spots. ( see picture ).
I'm guessing that it's some sort of deficiency, possibly potassium? Anyone like to offer their opinion?
Sorry about the reflection of my lights in the photo but the problem leaves are clearly visible.

 

[Zeus.]

H.Pinatifida can be tricky, some grow it like weeds other competent scapers struggle, I and others struggle to keep it healthy and it ends up looking like yours and have tried to get to the bottom of it, I think it doesn't like hard/very hard water- I have very hard water. I am about to take the RO route for water so it will be interesting for me to see if I can master H.Pinatifida

 

[Paul M]

H.Pinatifida can be tricky, some grow it like weeds other competent scapers struggle, I and others struggle to keep it healthy and it ends up looking like yours and have tried to get to the bottom of it, I think it doesn't like hard/very hard water- I have very hard water. I am about to take the RO route for water so it will be interesting for me to see if I can master H.Pinatifida

Thanks Zeus. I have soft water here, but I have seriyu stone in the scape. I periodically test the GH and get 8 degrees which I don't think is particularly hard. I am changing 25% water twice a week. I am using EA Aquascaper complete fertiliser but have knocked back the dosage somewhat over the past few weeks to slow down the growth rate on some of my faster growing stems which is why I suspected a deficiency. When I set up the scape the H.Pinatifida grew like a weed and I was regularly trimming it but it seems to be starting to suffer now. I'm going to start using a Nitrogen-free fertilizer and see how I get on. I think I have enough fish to provide for the nitrogen requirements of my scape.

 

[Zeus.]

Need to also decrease the light intensity or duration as its the amount of light that drives the amount of ferts needed. Seriyu Stone does drive the GH up quite a bit when using RO water. It will be dissolving the stone away as well, so it my be worth boosting the GH when you add the RO water to save your stone long term

 

[Paul M]

Need to also decrease the light intensity or duration as its the amount of light that drives the amount of ferts needed. Seriyu Stone does drive the GH up quite a bit when using RO water. It will be dissolving the stone away as well, so it my be worth boosting the GH when you add the RO water to save your stone long term

I'm trying to bring the lighting up a bit after knocking it back a long way shortly after starting the scape and getting diatom algae. I understand that it's a case of striking a good balance between light, CO2 and other ferts. The new fertiliser should be here tomorrow so I'll get on with dosing that and see how I get along over a few weeks. I have upped my CO2 recently so the drop checker is bordering on yellow by the end of the photoperiod. I'm reluctant to up it too much more for fear of killing my fish. although given that my plants are producing bubbles I think the oxygen levels must be pretty good.
I'll let you know how if things improve with the change of fertilizer routine.
Thanks for your advice it's greatly appreciated.

 

[Zeus.]

I'm reluctant to up it too much more for fear of killing my fish. although given that my plants are producing bubbles I think the oxygen levels must be pretty good

You can have good O2 levels and fish can still be gasping, as it the [CO2] that mainly drives respiration in many fish, its is because the increase in [CO2] decreases the pH of the blood in the fish which is dangerous. Apollo 13 was the classic example of this, the carbon scrubbers was damaged and CO2 levels was getting critical but plenty of O2, it got close to losing all the astronauts, but a make shift scrubber was made which reduced the CO2 levels.

Some fish do have O2 receptors in their gills, which we don't as its CO2 levels that drive respiration in mammals

 

[Paul M]

You can have good O2 levels and fish can still be gasping, as it the [CO2] that mainly drives respiration in many fish, its is because the increase in [CO2] decreases the pH of the blood in the fish which is dangerous. Apollo 13 was the classic example of this, the carbon scrubbers was damaged and CO2 levels was getting critical but plenty of O2, it got close to losing all the astronauts, but a make shift scrubber was made which reduced the CO2 levels.

Some fish do have O2 receptors in their gills, which we don't as its CO2 levels that drive respiration in mammals

Thanks for this Zeus. I didn't know the fish respiration info, although the Apollo 13 situation is well known to me, and not just from the movie.
Zeus quoting Apollo, now that's not something I expected when I joined this forum. 👍