I recently started a larger planted tank,120 gallons....I have followed the recomendations on this forum regarding lighting,ferts,CO2 ect. The tank is up and running. with CO2 my ph has dropped to 6.8 from 8.2 , my kh is 5.6 (100 ppm) everything seems to be falling into place. Except my gh which is still 14.5 (260 ppm). All my fish perfer soft acidic water...Currently they are enjoying hard alkaline tap water in smaller temp. tanks. They seem fine now (growing, very hungry), but I wonder about there long term health. I have read up on RO units. Seems like a quite of bit of expense, but maybe worth it in the long run. I have also come across water softening pillows that remove the hardness from your water. Sounds easy but maybe not the healthest for the occupents... fish and plants. Perhaps I should ignore the gh altogether and stick to plants that like hard water and keep the water perameters stable and let the fish adjust. I have been searching through the members planted tanks section and a good portion of the people seem unconcerned or don't know what there gh is. It has taken me quite a bit of time to get his far (carfully tested all the rocks with acid, changed from gravel to pure flouite base, eliminating anything that might increase the ph/gh) It would be nice to have all the parmeters ideal, but maybe that is just not realistic. Some or any advice would be great.

Unless you have very sensitive fish, say wild discus, then most fish will adapt to most water conditions. Commercially bred fish are normally quite hardy. If they are used to hard water and you dont get any health problems, then I would leave it be.

If you do want to lower the GH then RO water cut with tap is probably your best bet. The initial cost may be a bit but they are fairly cheap to run IME.

BTW a pH from 8.2 to 6.8 using CO2 will mean you have a fair amount of CO2 in the tank, watch for the fish gasping at the surface. If they do, reduce the bubble rate. 30ppm CO2 should give you a 1pH point drop. i.e. in your tank 30ppm Co2 should give you a pH of 7.2.

Sam

Thanks for the reply its great to get feed back. I have mainly loaches, Angels, and Gouramis maybe a ghost knife fish in the future, but I am still debating that. I kind of thought my ph drop was a bit much but the drop checker is still green....although I am using tank water, I was going to try a 4 dkh solution for more accuracy . I tried a ph/kh/CO2 chart and came up with 26.6 ppm, but that depends on my testing accuracy. All I have in the tank are a few guppies and they seem fine...I didn't want to subject the other fish to my experimentation.

The problem with the RO system would be I would have to hook up quite a storgage system with a float valve so I would have enough water for water changes (50 gallons or more), although I do like to fiddle.

Are chemicals a poor choice for long term consistancy? Probably yes, easy methods are usually flawed but I was wondering if anybody had some expierence with them and had encountered any problems.

An RO system is the way to go if you want to reduce the GH. How ever for the species mentioned its not necessary. Other chemicals are to expensive and its something you have to keep dosing. And it bepends on what chemicals the kits are using to reduce the GH.

I keep cardinals in GH of 16. I think that's about 330mg/l and they are fine. So I cannot see this affecting your angles.

If you need 50 gallons of RO you can make a float valve with some creative engineering and a toilets flushing mechanism and one of them Black plastic bins or galvanised from B&Q

Ok perfect ,that settles it then, no chemicals I didn't feel right about using them any way. Your right the fish seem quite content.....now on to the plants. How do your plants grow at that GH? What kind do you have? I will search for harder water species I am sure there must be a list of them some where on this forum. I found a list for fast growing starter plants, but I am not sure about their water parameters. More reasearch... I must say I do more of that than actual fish watching....although it is kind of fun, but time consuming.

Thanks

My plants are thriving.

I do does IE and inject CO2 but here is a list of plants that i currently have and are thriving in hard water.

Vallisneria nana
Anubias barteri v. barteri
Cardamine lyrata
Ceratopteris thalictroides
Hemianthus micranthemoides
Riccia (dwarf and fluitans)
Samolus valerandi
Alternanthera reineckii . Roseafolia

Thanks thats a big help...I will start my search.