KH too low

[cpn_aaron]

Hey all,
Well I've been testing and dosing my tank for about a week now with some of the ideas put forth from past posts and one I placed a week ago. With my dosing of macro adn micros more scientific I've already seena huge increase in plant health, color, adn they're growing pretty well. However, my KH is only about 2. I monitor my CO2 dosing (pressurized) and the KH never gets much above 2, maybe 3 sometimes. I wonder if this is too soft for my plants and may retard their growth or give the algae I've spent 7 months trying to defeat get another advantage.

I've monitored the past posts and seen people's opinions on how to higher KH. I could add crushed coral easy since I have many SW set ups and have some extra laying around in a stand somewhere, but if 2 is fine I'd like to just leave it at that. Thanks

 

[djlen]

The kH is a buffer, and has little to do with plant grow, but a lot to do with the safety of your fish when dosing CO2.
IMO, it should be raised to 3.0 - 3.5(better) as soon as possible to prevent a possible pH 'crash', a rapid drop in pH which could be dangerous to your fish.
Coral will bring it up slowly......baking soda will bring it up faster. 2 or 3 tbsps. of coral in your filter, in a filter bag will, in time bring it up. Then monitor it.
What size tank are we talking about?

Len

 

[daveedka]

I also might add What are your tap numbers for KH. If the tap is higher than the needed, the crushed coral is great. if it is lower then I'd do the baking soda to bring your change water higher. It takes very little baking soda, and works very quickly. I use 1 tsp per 30 gallons and it raises my Kh 1-2 ppm.
dave

 

[nekomi]

Jumping right in where I don't belong, but.. do you add the baking soda directly to the tank, or to the filter?

 

[djlen]

Through the filter is, IMO the better option.

Len

 

[daveedka]

I would agree through the filter, but I don't like adding it directly to a tank at all. I add it to change water which allows it to mix before being introduced. If you don't have a way to prep your water, that of course wouldn't work as well so the filter would be the next best option.
Dave

 

[cpn_aaron]

tank size is 55 gal. The tap water is lower than my desired KH, around a 1-2. Our county's water here in Fl is slightly acidic and soft. I may adda media bag of crushed coral to my canister filter and start using that with baking soda additions to change water. Would that bring the KH too high using coral to keep the main tank stable and higher and baking soda for quick KH controls? It is a buffer, but buffers can be sent to either extreme.

 

[daveedka]

You should be fine with that plan, one of the best things about the coral is that it is very slow, so it allows you to monitor and adjust. you will want to find a quantity that maintains the tank KH at the desired level, but it will be something you can do without a lot of risk. start out with a couple of TBSP in the filter and see if the KH goes up or down over time ( it is slow, so it may take a week or two to see a change). if it still drops, go with a little more, and vice versa. The baking soda added to the change water will put it a tank level gong in so the changes shouldn't have an adverse effect on your readings. With my tank and maintenance routine, Once I get my change water to 4 the tank stays at that level ( I change minimum 30% weekly and usually more than that), a lot depends on how often and how big the water changes are.
Dave

 

[djlen]

To increase the kH initially you could put the coral into the filter and also add 1tsp. of baking soda and test for content.

It will take the coral a week or two to start working on the water, at least for you to start seeing it's affect. Once it starts bringing it up you will have no need for the baking soda. I would use it initially to raise kH a point or so while you're waiting for the coral to take affect.

Keep monitoring your kH levels closely until you find out how the combination affects your water and then how the coral is holding the buffer for you. You can add or subtract coral as needed for affect. Over time, it will spend itself and need to be replaced or added to.

Len

 

[RTR]

Actually IME, over time it just gets coated with biofilm and becomes a bit less effective. Either boost the quantity a bit when that happens, or maintain two bags - one in and one out. When you clean the filters, leave the current wet bag out to dry. Next cleaning day, rinse the dry bag well (all the biofilms will be dead and dried) and put it back. This way for me the stuff last indefinitely. If we could select the right biofilm, an acid-producer should keep the same batch going much longer, but that only seem to happen in substrates, where the stuff would take forever to diffuse out - so we have to do work-arounds.