Glass or No Glass?

[Jim Fox]

I have a 55 gallon planted tank with several tetras, a couple of plecos, a Kissing Gourami, 3 albino cory fish and some nertile snails.  The aquarium is pretty stable and since I started using Easy Green and more recently, the Easy Root Tabs, the plants are doing better as well.  I have a Fluval 3.0 LED light.  I also have a pair of glass plates on top of the aquarium that I originally used to help reduce evaporation during the winter months and to keep the occasional fish from jumping out and ending their lives on the floor!  At this point, I am thinking of adding a couple of floating plants but wonder if I should remove the glass plates?  I am sure it would help the light penetrate better and I have read where floating plants do better without the glass plates on top.

Appreciate input from others and their experiences with this issue and floating plants.

[CJs Aquatics]

depending on the floating plant, it will do better without the glass plate on top. I’ve found that once your aquarium is well established things are less likely to jump. Perhaps there is no harm in attempting to grow the floating plants with the plates, however if it were me, I would get them started, then remove the plates bc floating plants also encourage things to stay put. They can also indicate water quality issues for you as well as in my opinion look more natural. 

[Seattle_Aquarist]

Hi @Jim Fox

I have access to an Apogee MQ-510 PAR Meter which measures light intensity.  I've tested light intensity several times using both florescent and LED fixtures.  You did not mention how thick your glass is but I can tell you that the amount of light lost through a 1/8" think glass top (I use Aqueon Versa-Tops).  Here is what I have reported in the past:

Quote

The results were interesting. It was a standard 30 gallon (36" length) with an 2X36 watt (6700K) AH Supply kit over a Aqueon Versa-Top. With new bulbs and no glass top the PAR = 110; with "dirty"* Versa-Top in place PAR = 96; with cleaned Versa-Top in place PAR = 101. All readings were taken with new bulbs @ substrate level about 13 inches below the fixture.

*dirty = lots of dried water spots on top, condensation; dust

If the glass is clean with no build-up of dust or mineral deposits the amount of light lost is +/-10%. 

As for floating plants growing better without a glass top I think it would depend upon the species, my watersprite and Salvinia minima do just fine with a glass top in place.  Hope this helps! -Roy

Edited August 28, 2022 by Seattle_Aquarist

[Jim Fox]

Thanks for the feedback.  I think that it is time to remove the glass plates for a while and see what happens.  

[Patrick_G]

I’ve found that dwarf water lettuce likes the high humidity created by the lid. I have much better results growing it with the lid on. 
 

 

[Scapexghost]

I've had a lot of success with water lettuce with a lid, high flow and surface agitation are much more detrimental. 

Glass is much clearer than water. I wouldn't worry about the light being blocked by 3/8" of glass when you have 12"-24" of water blocking light.