Am i missing something?

Hi @NeilB, Thanks for the info. At the moment the Co2 is measured and its stable lime green at 3bps so i don't see a need to up the CO2 as i dont want to endanger any of the livestock in the tank. Also i need to mention the the Co2 checker is on the opposite side of the tank to where the Co2 diffuser is fitted.

Pearling is another thing on its own lol, my plants hardly ever pearl but yet they grow fast and healthy; At one stage i was trimming my Hygophillia Difformis every 3rd day. I have had a pearling discussion on here before and many users mentioned that their plants grew perfectly but did not pearl.

Guess its one of those things bud.

 

15,000k is in the blue light spectrum. The Kelvin rating enters the blue spectrum at about 8,000k. 15,000k is bang smack between 480 and 490nm. Refer, CIE 1931 x,y chromaticity space.

As far as our aquarium plants go, their photosynthetic ability is most sensitive between 650 and 680nm. 400 to 490nm is used by both plants and algae. Refer pg 56; Aquarium Plants; Hiscock, Peter; 2003. Interestingly, at 500nm (which is Green light) most plants reflect light. To further emphasize the use of blue light by algae, let’s consider corals. Light found on coral reefs is typically 440-490nm and hence 10,000; 12,500; 15,000; 20,000k light is recommended for saltwater reef aquariums. But why? Coral contain Zooxanthellae which is a microscopic single celled marine algae that lives in symbiosis with the coral. Refer pg 326-330 and 417; Aquarium Corals; Borneman, Eric; 2001.

So, simply put, 15,000k light encourages algae growth.

Bridgelux and Cree are very good and you cant go wrong with those. However, you cannot compare the effectiveness of a 1w Cree/Bridgelux LED on a water depth of 17/19cm in 1ft tank to 50/55/60cm water depth on a 600L tank. Personally, I only use Metal Halides on my tanks which are 60cm and more in depth. My planted tanks that have LED’s are 40cm max depth. Without proper PAR readings, you cannot assume that that LED fixture is providing adequate light for carpeting plants.

Lighting, CO2, temperature. Get these right and together with ferts you should grow just about any plant. Only other thing I can think of to get your GC growing is perhaps to use undergravel heating cables to keep the roots warm – S Repens does have a heavy root system, if I remember correctly.

Ps. Pearling is a very good indicator that plants are in a conducive environment. Hygrophyllia is a terrible yard stick as they grow crazy with the most basic lighting and setup.

 

This may be a stupid question, but have you tried trimming?

 

Very good info here and i appreciate the link CIE 1931 (Very neat!), So on that basis i completely agree that the 15000K is out of the Photo Peak range although it will still be part of the growth but as you say it will lead to Algae spores; good to know this now..

Of course they wont be the same over a different distance however i have 6 x 30w 6500K led chips that take care of the depth issue and as i mentioned the surface is getting plenty of usable light; however taking this on a ran a 50w LED spotlight basically on the glass in front of the ground cover and to be honest i hardly noticed a good change in brightness but also did not see any pearling; now i cannot exclude that the glass might be reflecting the majority of the light but i really have no other method of testing it before getting a PAR Reading. I will be lowering the Led system by 10cm for now; i did do a temp 10cm drop to see if there was a good change in surface light and it's around 10% brighter which is odd since the 50w spot did not do much (hence tank glass reflection?)

So with the other theories posted; i have left the tank wc for longer periods and have done minimal tops ups as well.

I had a look today and have seen that all the Starougyne repens has got new leaves and the HC has started sprouting new leaves too.
I will continue too use the ADA ferts as i have seen a good colour and growth increase in all the plants.

Yes Hygro is really not hard to grow and it is rocketing already; has a really nice texture though.

Will update you all next week and see what improvements have happened.

Cheers

 

Not much to trim.

 

Nice .. good to hear you are seeing some new growth.

Later Ferdie