API tap water conditioner and plants

[Fishy_Dan]

Hello,

I switched to using API tap water conditioner a while ago as the one I was using "includes natural extracts to improve fish health". It gave no more information than that and no list of ingredients. I've heard that aloe vera can cause problems for labrynth fishes, so out of precaution switched to API.

Since then my salvinia died off badly and I have had a problem with black algae. The type that covers leaves and is very tough to rub off.

I am running a low tech setting so I was only dosing very small amounts of seachem flourish comp.

I think I have figured out that the API water conditioner is also removing heavy metals from the water and this was causing the salvinia to die off and black algae to grow.

So I've started dosing more flourish comp and the salvina is starting to come back, although at the cost of some green hair algae.

I wonder if anyone else has had this problem with API water conditioner? And whether I was right to move away from the other dechlorinator?

D

 

[Essjay]

I have use that conditioner for years and don't have a problem.

But like most water conditioners it does contain a chemical to bind metals, which will bind the trace metals in fertiliser. A very knowledgeable member on here advises to add fertiliser the day after a water change, and not the same day; that works for me.

Edit - forgot about the algae - it won't be the water conditioner causing that but something out of balance - too much fertiliser or too little; too much light or too little.
Can you tell us:
how big is the tank
what plants you have besides the salvinia
how much Flourish Comprehensive you add
how long the tank lights are on for
whether any sunlight shines on the tank

This info should help to work out what's causing the algae.

 

[Fishy_Dan]

A very knowledgeable member on here advises to add fertiliser the day after a water change, and not the same day; that works for me.

Aha! I think this could be the solution. I'll be sure to wait before adding the ferts.

I imagine the algae problems are a consequence of the salvinia dying off. Less surface coverage means more light, which is likely the reason for the algae.

I have just reduced the light intensity with a dimmer switch, once the salvinia grows back I'll put it back up.