spinex

Hello,

By the way, i'm a newbie so please bear with me.

I got a Nano tank around 45cm x 23 x 25cm. Which can hold around 23 litre/ 6 gallon of water. Initially i used some pellet like base fertiliser from Oceanfree recommended by LFS and used lapis sand as substrate. There are some plants inside (nanas, taiwan moss and java moss, Hygrophila difformis) and a driftwood and the PH is really low around 6 and sometimes 5.8. Plants are growing slowly but doing fine even after more than a month. I suspect the driftwood is causing the low PH because i put the same driftwood to a pail of water (PH7.3-7.5) it turn to 6.3 range after a few days. Using this setup, my guppies survived and doing well but my cherry or malayan shrimps have a hard time surviving.

Recently i revamp my landscape and got myself Seachem Onyx sand (7kg) as substrate and reuse back the pellet like base fertiliser and the result is very high PH of 8 even with the same driftwood in place. The water from my tap PH is 7.3-7.5 range. I also added some baking soda with advice from my LFS to stabilise the PH since he told me our local water is having a KH0.

Since i like to put some shrimps into my NANO. I doubt they will do well in a PH8 water. So far for my new setup using Onyx sand i haven't put any shrimps in but my guppies are doing fine.

Do i wait for a month to see what's the PH or should i add some peat to buffer the PH ? I do not want to kill all the shrimps again

Thanks for any advice in advance. Btw i do dose some Excel and Flourish. Lighting is 28W, 8000k.

gnome

You don't need to add baking soda because the Onyx substrate is buffering the water (elevating GH as well as KH). This is why your pH is going up.

Shrimp can tolerate a pH of 8 quite easily. In fact, they are said to prefer alkaline water. They fare poorly in acidic conditions, and below about 6.6 is actually pretty dangerous for them. Some manage to keep cherry red shrimp in pH as low as 6.0, but I doubt that they like it, and I would think that the drop in pH would have to be very gradual.

28W over 6 gallons seems like a little much... But that's just me. I keep plants quite successfully in my 2.5 gallon tank using only an 8W regular fluorescent strip light.

Flourish and Excel are fine. You might want to check the contents of the base fertilizer. Maybe something in that is killing the shrimp. BTW, shrimp also cannot tolerate high levels of nitrate. Copper is a sure killer, but the amount in Flourish (Comprehensive) are fine unless you're dosing way more than recommended.

-Naomi

spinex

Gnome,

Thanks for your help. I will do some water change graudually and monitor the PH and feedback. Of course this time i won't add any baking soda anymore

spinex

Did a 30% water change when the PH is at 7.8. Tap water is measured at 7.4.
After 8 hrs later measured the PH now it's at 7.1. Seem good.

gnome

Whoa - that's strange... Usually, pH goes *up* because any CO2 that would be in the tap water degasses with time. Oh well - not that it's a problem. I wish MY tap water would do that . You're not injecting CO2? And did you ever put that driftwood back into the tank? You know, you probably could have kept the old set-up with the driftwood and just raised the KH and GH with crushed coral or something.

Once your pH stabilizes, you can try to introduce a few shrimp into your tank. If your losses are still significant, it's probably the fertilizers.

-Naomi

spinex

Back to my old threadt. Yup the driftwood is never removed and i using seachem onxy now. Everything seem much more stable nowadays. Will be dosing CO2 from cylinder from next week. I used to have Excel as my source of CO2 previously but seem like not all plants can do well with it.

gnome

That's cool. Yeah, Excel is generally a sufficient souce for carbon in a low-light set-up, in which nutrients are not being taken up as fast. If you're still using 28W over the 6 gallons, that doesn't exactly put you in the "low-light" category. At the recommended dosage, it's only providing about 1/3 the carbon that CO2 injection would. I've used double the dosage without any dire effects, and some use 3x, but I wouldn't advise it, especially if you're going to be keeping shrimp or any other "sensitive" critters/fish species. Besides, at some point, it's just no longer economical - you'll be using it up too fast.

Speaking of shrimp, have you gotten any, yet? They should be pretty happy in your set-up, now.

Thanks for the update!

-Naomi